120104d Welder Geometric Formulas Trade Math First Period Table of Contents Objective One ............................................................................................................................................... 2 Key Terms ................................................................................................................................................. 2 Order of Operations in Solving Equations ................................................................................................ 3 Solving Equations ..................................................................................................................................... 4 Objective One Exercise................................................................................................................................. 6 Objective Two............................................................................................................................................... 7 Perimeter ................................................................................................................................................... 7 Area ......................................................................................................................................................... 13 Volume .................................................................................................................................................... 23 Objective Two Exercise .............................................................................................................................. 27 Objective Three ........................................................................................................................................... 39 Calculating the Weight of a Solid ........................................................................................................... 39 Objective Three Exercise ............................................................................................................................ 42 Objective Four ............................................................................................................................................ 45 Capacity of an Object .............................................................................................................................. 45 Objective Four Exercise .............................................................................................................................. 47 Self-Test ...................................................................................................................................................... 50 Self-Test Answers ....................................................................................................................................... 54 Objective One Exercise Answers................................................................................................................ 55 Objective Two Exercise Answers ............................................................................................................... 55 Objective Three Exercise Answers ............................................................................................................. 57 Objective Four Exercise Answers ............................................................................................................... 57 NOTES Geometric Formulas Rationale Why is it important for you to learn this skill? Many of the products you will work on in the shop or on the jobsite are made up of regular geometric shapes like circles, squares or triangles. Whether you work on an oil storage tank, a hopper or a truck bed, you will eventually need to calculate perimeter, area, volume, weight or capacity. You may need these calculations to establish cost or quantity of materials or to determine the size of an object after you fabricate it. Outcome When you have completed this module, you will be able to: Solve problems involving geometric formulas. Objectives 1. 2. 3. 4. Identify terms and concepts used in working with formulas. Identify formulas and solve problems for perimeter, area and volume. Calculate the weight of a solid. Calculate the capacity of a container in gallons and litres. Introduction This module addresses the terminology and concepts you will need to identify common formulas and solve problems for finding perimeter, area and volume. It also addresses how to use the volume calculation to determine the weight of a solid and to convert to gallons and litres to find capacity. 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 1 NOTES Objective One When you have completed this objective, you will be able to: Identify terms and concepts used in working with formulas. Key Terms The following terms are used throughout the trade. To work effectively with equations, you should be familiar with them. Term Definition equation A statement or mathematical expression that uses an equal sign to indicate two related quantities have the same value. All equations must be true. 5 3 4x 2 n 2 64 formula A law or rule that you express as an equation. A formula expresses some fundamental fact or truth. Area Length x Width Volume = r2h constant A numerical value that forms part of an equation or formula. It is a value that cannot change. In the following examples, 2 and are constants. P 2L 2W C = d variable A symbol or letter that represents an unknown quantity in an equation or formula. A variable has different values depending on the problem, such as the radius of a circle (r) or the length of the side of a square (s). A = r2 P = 4s term The parts of an equation or formula separated by addition, subtraction or equal signs. A term can be a single constant or variable (A). A term can be two or more constants and variables that you multiply together (2r2) or it can include division (12bh). A 1 bh 2 A = 2r2 + LW solution A replacement for a variable or unknown that makes an equation true. To find the solution is the reason why you do all the calculations. 2 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES Order of Operations in Solving Equations When you solve for an equation that has two or more mathematical functions, you must follow a standard order of operations. An acronym to describe the order of operations is Brackets, Exponents, Division, Multiplication, Addition and Subtraction (BEDMAS). These letters indicate the order in which you must perform the operations. 1. Brackets 2. Exponents 3. Division 4. Multiplication 5. Addition 6. Subtraction You can sometimes confuse the multiplication symbol in standard arithmetic with the symbol x that you use as a variable. You can use brackets or no brackets at all, instead. For example, when you see the following in a mathematical equation, solve it like you would a multiplication problem. 3(38) 114 You may also see multiplication problems expressed without brackets, like LW, which means length times the width. Example 1 The following example shows how you solve using BEDMAS, with the mathematical . n 8 – 3 2 20 5 n 8 – 6 20 5 n 8 – 6 4 n 2 4 n 6 Calculators follow this order of operations, so you must take care when you input a series of numbers and functions. Perform division and multiplication operations as they occur from left to right. Then perform addition and subtraction operations as they occur from left to right. Example 2 The following example shows how you solve using BEDMAS, with the mathematical and brackets. n 3[5 9 – 4 3] n 3(5 9 – 7) n 3 45 – 7 n 3 38 n 114 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 3 NOTES NOTE When brackets surround any group of terms, you must perform the functions inside the brackets first. If there is more than one set of brackets, perform the operation within the inner set first and the operation within the outer set last. Example 3 The following example shows you find the area of a circle with a radius of 5 inches, using BEDMAS and brackets. A r 2 A (5" 5") A 78.5 in 2 NOTE You will encounter an exponent when finding the area of a circle (A = r2). You must find r2 before you multiply by . There is a big difference between r2 and (r)2 if r is not equal to 1. Solving Equations In order to solve a simple equation, isolate the variable or unknown on one side of the equation. An equation is equal on both sides; therefore, if you add or subtract on one side, you must add or subtract the same amount on the other side. You can also multiply or divide every number in an equation by the same number. The objective of these operations is to isolate the variable so that you have a solution to the equation. Example 1 Solve for the unknown variable (n) in the following equation. 6n – 7 n / 2 15 To solve for this equation, do the following. 1. Add 7 to both sides. 6n – 7 7 n / 2 15 7 6n n / 2 22 2. Multiply all terms by 2. 2 6n 2 n / 2 2 22 12n n 44 3. Subtract n from both sides. 12n – n n – n 44 11n 44 4. Divide all terms by 11. 11n 11 44 11 n 4 4 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES Example 2 You want to build a welding shop with an area of 2000 square feet. If you must limit it to a width of 32 feet, what is the length of the shop? Solution To solve, consider the following. Area = Length x Width 2000 ft2 = Length x 32 feet Divide both sides by 32 feet. 2000 ft2/32ft = Length x (32 feet/32 feet) 62.5 feet = Length 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 5 NOTES Objective One Exercise 1. Define equation. 2. Define formula. 3. Define constant. 4. Find the value for P in the formula P = L x W, if L = 43.7 and W = 13.2. 5. Find the value for L in the formula P = L x W, if P = 56 and W = 7. 6. Find the value for A in the formula A = r2, if = 3.14 and r = 3.5. 7. Find the value for A in the formula A = h 8. Find the value for h in the formula A = h ( B 2 b ), if h = 6, B = 10 and b = 5. ( B 2 b ), if A = 210, B = 23 and b = 7. 9. Find the value for H in the formula V = LWH, if V = 3600, L = 40 and W = 20. 10. Find the value for h in the formula V = r2h, if V = 251.2, = 3.14 and r = 5. 6 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES Objective Two When you have completed this objective, you will be able to: Identify formulas and solve problems for perimeter, area and volume. Perimeter Perimeter is the distance around any geometric figure, such as a square, rectangle, triangle, trapezoid, parallelogram, circle or semicircle. Any piece of material in the welding trade could be a geometric figure or a combination of two or more figures. You can use perimeter to determine cost or quantity of material that you require. When the figure is a circle, you call the perimeter the circumference. Perimeter of a Rectangle A rectangle is a four-sided figure; its interior angles are all right angles (90°) and its opposite sides are parallel and equal in length (Figure 1). Figure 1 - Rectangle. NOTE The little squares inside the rectangle in Figure 1 (and similar illustrations) denote a right angle. To find the perimeter (P) of a rectangle, add the two lengths and the two widths. You can express the formula in the following ways. P L L W W P 2L 2W P 2 L W Example Find the perimeter of the rectangle in Figure 2 in centimeters (cm). Convert to similar units; for example, 10 mm equal 1 cm; therefore, 216.9 mm equal 21.69 cm. Figure 2 - Perimeter of a rectangle. 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 7 NOTES To solve, do the following. P 2L 2W P 2 58.2 cm 2 21.69 cm P 159.78 cm Perimeter of a Square A square is a rectangle that has four equal sides in length (Figure 3). Figure 3 - Square. To find the perimeter of a square, add the length of each side (s). You can express this formula in the following ways. P s s s s P 4s Example Find the perimeter of the square in Figure 4 in feet and inches. Figure 4 - Perimeter of a square. To solve, do the following. P = 4s P = 4(478") P = 1912" P = 1' 712" 8 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES Perimeter of a Triangle A triangle is a figure that can take several different shapes, but always consists of three straight lines. Right Triangle A right triangle (or right-angle triangle) is a triangle that has one 90° angle (Figure 5). The sloping line opposite the right angle is the hypotenuse. Figure 5 - Right triangle. 3-4-5 Triangle A 3-4-5 triangle is a right triangle that you can use in shop layout for squaring frames or structural members. The hypotenuse is 5 units of length and the other two sides are 3 and 4 units of length. You can also use multiples of 3-4-5 as dimensions, such as 9-12-15. Equilateral Triangle An equilateral triangle includes sides that are the same length and angles that all equal to 60° (Figure 6). An equilateral triangle is one of the strongest shapes in nature, so you often use them in fabricating. Figure 6 - Equilateral triangle. 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 9 NOTES Isosceles Triangle An isosceles triangle is a triangle in which two of the three sides are of equal length and two of the three angles are equal (Figure 7). Figure 7 - An isosceles triangle. Scalene Triangle A scalene triangle is a triangle that has no equal sides or equal angles. All three sides are different lengths and all three angles are different values (Figure 8). Figure 8 - Scalene triangle. To find the perimeter of any triangle, add the lengths of the three sides (A, B and C). You can express this formula in only one way. P A B C Example Find the perimeter of the triangle in Figure 9 in feet and inches. Figure 9 - Perimeter of a triangle. 10 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES To solve, do the following. P A B C P 231 / 8 " 193 / 8 " 101 / 4 " P 523 / 4 " P 4' 43 / 4 " Circumference of a Circle A circle is a closed curved line on a flat surface in which every point is the same distance from a fixed given point called the centre. Figure 10 lists some basic terminology you must know when dealing with circles. The circumference is the distance around a circle. The diameter is the straight-line distance across a circle and passes directly through the centre. If you divide the diameter by 2, you get the radius. The radius is the straight-line distance from the centre to the edge of a circle. If you multiply the radius by 2, you get the diameter. The symbol (pi) is a number approximately equal to 3.1416 and it is the circumference divided by the diameter. Figure 10 - Circle. For most calculations, you can use = 3.1416; however, it is faster and more accurate to use the button on a calculator because it fills the display ( = 3.141592654). You have to be careful when doing calculations involving because your answers will vary slightly depending on the value that you use for (how much you round it). To find the circumference (C) of a circle, multiply the diameter (d) by . The diameter is equal to two radii; therefore, you can write the formula as C = 2r. C d C 2r 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 11 NOTES Example Find the circumference of the circle in Figure 11 (round to two decimal places). Figure 11 - Circumference of a circle. To find the circumference of the circle in Figure 11, you can perform either of the calculations in Table 1. C d C 2r C 7.2 m C 2() 3.6 m C 22.62 m C 22.62 m Table 1 - Solutions for determining the circumference of a circle. Perimeter of a Combined Geometric Figure You may need to find the perimeter of objects that are a combination of two or more geometric figures. In these cases, divide the object into its geometric component parts. Example You have to order enough fencing to enclose a skating rink (Figure 12). Figure 12 - Skating rink. 12 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta If you remove the two end pieces, each a semicircle (half circle), and place them together (Figure 13), they form a whole circle. The remaining part will have the shape of a square. NOTES Figure 13 - Perimeter of a skating rink. The distance around the skating rink then becomes the circumference of the circle plus two straight lengths of 180' each. C = d C = (180') C = 565.487' Therefore, the total length of the fence you require for the skating rink is as follows. 565.487 + (2 x 180) = 925.487' Area Area is the amount of material it takes to cover a surface. Area uses two dimensions that must always be in the same units. For example, if you use millimetres or centimetres for distance, the area then becomes square millimetres (mm2) or square centimetres (cm2), respectively. You must sometimes convert units to make them the same. Area of a Rectangle Figure 14 represents a rectangle with a length of 5' and a width of 4'. Figure 14 - Area of a rectangle The rectangle divides into small squares, one foot on each side, so each small square represents 1 ft2. Since there are four rows of squares each containing 5 ft2, the area becomes 4 x 5 = 20 ft2. This method of calculating area works with any lengths, including fractions and metric measure. The formula for finding the area (A) of a rectangle is equal to the product of its length (L) and its width (W), which is A = LW. 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 13 NOTES Example Find the area (mm2) of the rectangle in Figure 15. If 1 cm = 10 mm, then 58.2 cm = 582 mm. Figure 15 - Area of a rectangle. To solve, do the following. A LW A 582 mm 216.9 mm A 126 235.8 mm2 Area of a Square A square is a special rectangle with all four sides equal in length. If you multiply the length by the width (which are the same), you find the area (A) of a square. You are multiplying one side (s) by another side (s) or you are squaring one side (s2), as the equations show. A sxs A s2 Example Find the area of the square in Figure 16. Figure 16 - Area of a square. To solve, do the following. A s2 A ( 47 / 8 ") 2 A 2349 / 64 in 2 14 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES Area of a Triangle You can think of a triangle as a rectangle that you cut exactly in half (Figure 17). Instead of using length and width (as with a rectangle), you use base and height when calculating the area of a triangle. The height of a triangle is its altitude. Figure 17 - Area of a triangle. Since a triangle is equal to half the area of a rectangle with length equal to base and width equal to height, the formula for finding the area (A) of a triangle is half (1/2) of the product of the base (b) and the height (h). Either of the following equations will result in the correct answer. A 1 / 2 bh bh A 2 These formulas hold true for any triangle. Figure 18 illustrates the height for triangles that are not right triangles. NOTE The base and height must be perpendicular to each other. Figure 18 - Height of a triangle. 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 15 NOTES Example Find the area of the triangle in Figure 19. Figure 19 - Finding the area of a triangle. To solve, do the following. A 1 / 2 bh A 1/ 2 231 / 8 " (81 / 2 ") A 989 / 32 in 2 Area of a Circle To find the area of a circle, you must know the radius. If you know the diameter, you can divide it by 2 to find the radius (Figure 20). The formula to find the area (A) of a circle is as follows. A r r A r 2 Example Find the area of the circle in Figure 20 (round to two decimal places). Figure 20 - Finding the area of a circle. To solve, do the following. A r 2 A 3.6m 16 2 A 40.72 m2 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES Area of a Trapezoid A trapezoid is a figure that has only one set of parallel sides. These two sides are the bases (large base [B] and small base [b]). The height of a trapezoid is the perpendicular distance between the bases (Figure 21). Figure 21 - Bases of a trapezoid. One way to determine the area of a trapezoid is to remove the small triangles from each bottom half of the trapezoid and reattach them to the upper corners to form a rectangle (Figure 22). Figure 22 - Area of a trapezoid. In Figure 22, the length of the newly formed rectangle is 11", which is the average length of the large base and the small base. The area of a rectangle is length times width (LW); therefore, to find the area (A) of a trapezoid, you find the average of the two bases (B + b)/2 and multiply by the height (h). The bases are the parallel sides and the height (B b) must be perpendicular to the bases. Use the equation A h . 2 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 17 NOTES Example Find the area of the trapezoid in Figure 23. If 12" is 1', then 7' 9" is equal to 7.75' and 31' 6" is equal to 31.5'. Figure 23 - Finding the area of a trapezoid. To solve, do the following. Ah B b 2 31.5' 16' A 7.75' 2 2 A 184.0625ft Area of a Parallelogram A parallelogram has four sides. The sides opposite each other are the same length and are parallel and the angles opposite each other are equal. The height of a parallelogram is the perpendicular distance between two sides (Figure 24). Figure 24 - Area of a parallelogram. If you were to cut the parallelogram along the dotted height line and reassemble it on the other end, you would create a rectangle. The height of the parallelogram would be equal to the width of the rectangle and the base of the parallelogram would be equal to the length of the rectangle. To find the area (A) of a parallelogram, you multiply the base (b) with the perpendicular height (h). Do not use the slant height for finding area. 18 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES Example Find the area (cm2) of the parallelogram in Figure 25. If 1 m = 100 cm, then 0.23 m = 23.0 cm. Figure 25 - Finding the area of a parallelogram. To solve, do the following. A bh A 23.0 cm 9.4 cm A 216.2cm2 Lateral Surface Area of a Cylinder The lateral surface area (LSA) of any solid is the surface area of the sides (walls). It does not include the area on the top and/or bottom. You should use the following calculations only for cylinders with uniform cross-sections (same shape from top to bottom) and with sides that are perpendicular to the bases. Figure 26 is an illustration of a cylindrical tank with the shell rolled out flat to make it look like a rectangle. Figure 26 - Lateral surface area of a cylinder. You can find the area of a rectangle by multiplying the LW. In Figure 26, the length of the rectangle is actually the circumference of the circle, which you calculate by multiplying with the diameter. Therefore, the formula to find the lateral surface area (LSA) of a cylinder is as follows. LSA dh LSA 2rh 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 19 NOTES Example Find the lateral surface area (ft2) of the cylinder in Figure 27. Figure 27 - Finding the lateral surface area of a cylinder. To solve, do the following. LSA dh LSA 1.5' 4' LSA 18.85 ft 2 Total Surface Area of a Closed Cylinder The total surface area (TSA) of a closed cylinder includes the lateral surface area and the area of both ends, which are circles. You must add the area of the ends (both circles) to the area of the lateral surface. TSA dh 2( r 2 ) Example Find the total surface area (in2) of the cylinder in Figure 28. Use π = 3.14 for this example. Figure 28 - Finding the total surface area of a cylinder. 20 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES To solve, do the following. TSA dh 2( r 2 ) TSA 3.14 18" 48" 2 3.14 9" 2 TSA 2712.96 in2 508.68 in 2 TSA 3221.64 in 2 Lateral Surface Area of a Right Rectangular Solid A right rectangular solid has a rectangular base with sides that are perpendicular to it. You can find the lateral surface area by finding the area of each of the four sides and then adding these areas together. You could also add the two lengths and the two widths together and then multiply this sum by the height. It is similar to rolling out the outer shell to make it one large rectangle. In this case, the lateral surface area is the perimeter of the base multiplied by the height. Figure 29 illustrates the pieces of the rectangular shape that make up the lateral surface area. Figure 29 - Lateral surface area of a rectangular solid. To find the area of the two large sides, you multiply length (L) by height (H) of both sides. To find the area of the two ends, you multiply the width (W) by the height (H) of both ends. You can state the formula in two different ways. LSA 2LH 2WH LSA 2 LH WH Using the perimeter to find the lateral surface area, you can also state the formula in two other ways. LSA H L L W W LSA H 2L 2W In all cases, finding lateral surface area of any solid, regardless of the shape of the base, is a matter of finding the perimeter of the base and multiplying the perimeter by the height. 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 21 NOTES Example Find the lateral surface area (in2) of the rectangular shape in Figure 30. Figure 30 - Finding the lateral surface area of a rectangular solid. To solve, do the following. LSA 2LH 2WH LSA 2 32 28 2 14 28 LSA 1792 784 LSA 2576 in 2 Total Surface Area of a Right Rectangular Solid The TSA of a right rectangular solid includes the lateral surface area plus the area of the top and bottom, which are rectangles. You have to add the area of the top and bottom to the area of the lateral surface. To find the area of the top and bottom, multiply length (L) by width (W), as the equation shows. TSA 2LH 2WH 2LW Example Find the total surface area (in2) of the rectangular shape in Figure 31. Figure 31 - Finding the total surface area of a rectangular solid. 22 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES To solve, do the following. TSA 2LH 2WH 2LW TSA 2 32 28 2 14 28 2 32 14 TSA 1792 784 896 TSA 3472in 2 Volume Volume is the amount of space that an object occupies. You most often use volume to mean capacity or the number of cubic units enclosed within an object like a bin or tank. Before you can calculate the volume of any object, you must ensure that the measurements are in the same units. Volume of a Right Rectangular Solid When calculating the volume of a right rectangular solid, use the length, width and height. For example, if you have a cube that is 12" by 12" by 12" (Figure 32), you want to find the number of one-inch cubes that will fit in the large cube. You can also find the area of the base and multiply that area by the height. Figure 32 - Volume of a rectangular solid. In the case of a cube, which has all equal sides, you can find the volume (V) by cubing the length of one side (s3). V s s s V s3 If you have a right rectangular solid, you find the volume (V) by multiplying the length (L) by the width (W) by the height (H). V LWH 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 23 NOTES Example Find the volume of the rectangular solid in Figure 33 using both in3 and ft3. Ensure that all dimensions are in the same units. 2 yards = 6 ft = 72". Figure 33 - Finding the volume of a right rectangular solid. To solve, use Table 2. Solution in in3 Solution in ft3 V in 3 LWH V ft 3 LWH V in 3 72" x 30" x 6" V ft 3 6' x 2.5' x 0.5' V in 3 12 960 in 3 V ft 3 7.5 ft 3 Table 2 NOTE 1 ft3 = 1728 in3. Volume of a Cylinder To find the volume of a cylinder, you must first find the area of the base and then multiply that area by the height. The height is the measurement that is perpendicular to the round end, no matter which way the tank lies (Figure 34). Figure 34 - Volume of a cylinder. 24 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta You use the formula A = r2 (where the radius is half the diameter) to find the area of a circle. To find the volume (V) of the cylinder, multiply the area of the base (r2) by the height (h). NOTES V r 2 h Example Find the volume (ft3) of the cylinder in Figure 35 rounded to two decimals. V r 2 h V 52 16 V 1256.64 ft 3 Figure 35 - Finding the volume of a cylinder. Volume of any Regular Shaped Object You calculate volume by finding the area of the base and multiplying it by the height. You can determine the volume of any object with a uniform cross-section by calculating the area of the cross-section and then multiplying it by the height. Figure 36 shows some examples of these shapes. Figure 36 - Uniform cross-section figures. For all objects that have a uniform cross-section, you can find the volume by finding the area of the base and multiplying by the height. You can also break the object into familiar shapes and find the volume of each familiar shape and then add them together. 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 25 NOTES Example Find the volume of the semicircular tank in Figure 37, rounded to two decimal places. If you look closely at this tank, you will see that it is actually a tank with two half cylinders at each end and a solid rectangle in the centre. To find the volume, either: find the area of the base and multiply by the height or find the volume of the two half cylinders and the volume of the rectangular centre and add them together. Figure 37 - Semicircular tank. To solve, use Table 3. Area of Base × Height Cylinder Volume + Rectangle V ( r 2 LW ) H V r 2 H LWH V r 2 (9 4) 14 V 22 14 9 4 14 No Addition V 175.93 504 V 679.93 ft 3 V 679.93 ft 3 Table 3 NOTE You can treat the two half cylinders like one cylinder. 26 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES Objective Two Exercise Perimeter 1. Define perimeter. 2. You use the formula P = 2L + 2W to find the perimeter of what figure? 3. Which formula do you use to find the circumference of a circle? 4. Find the perimeter of the square in Figure 38 Figure 38 5. Calculate the perimeter (feet and inches) of a square tank bottom that measures 2' 81/4". 6. Calculate the perimeter (metres) of a rectangle with a length of 450 cm and a width of 1800 mm. 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 27 NOTES 7. Determine the perimeter (centimetres) of the rectangular holding tank bottom in Figure 39. Figure 39 8. Calculate the perimeter of a triangle (feet and inches) to the nearest 1/16". It has dimensions of 50.6', 69' and 103.5". 9. Determine the perimeter (centimetres) of the triangle-shaped neon sign frame in Figure 40. Figure 40 28 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 10. Find the circumference of each of the following circles to the nearest 1/64". (Use π button). a) d = 14" NOTES b) r = 12" c) r = 3.25" d) r = 6.5' e) d = 2' 21/2" 11. What is the circumference of the tank lid in Figure 41 to the nearest 1/16"? (Use π button). Figure 41 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 29 NOTES 12. Figure 42 shows the shape of a storage yard for a welding shop. Calculate (feet) the amount of fencing that you require to enclose the yard completely. Figure 42 13. You must place a drainage pipe around the foundation of a building (Figure 43). What is the total length of drainage pipe that you require if you allow 15' for waste and corners to the nearest 1/16"? (Use π button). Figure 43 30 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 14. You are fabricating a semicircular-ended tank. The bottom comes from 1/8" steel plate stock with the dimensions in Figure 44. What length of material (inches) do you require to form the sides of the tank to the nearest 1/64"? (Use π = 3.1416.) NOTES Figure 44 Area 1. Define area. 2. What formula do you use to find the area of a triangle? 3. You use the formula A = s2 to find the area of what figure? 4. The lateral surface area of a rectangular solid includes adding together the area of how many surfaces? 5. What formula do you use to find the total surface area of a cylinder? 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 31 NOTES 6. Determine the area (in2) of the pieces of sheet metal in Figure 45. Round your answers to the nearest 116". Figure 45 2 7. Find the area (ft ) of a square building lot that measures 76 yards on one of its sides. 8. A piece of carpet measures 12' x 15'. Find its total cost at $22.50/yd2. 9. Calculate the area (ft2) of a triangle if the base is 36" long and the height is 8". 32 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 10. Calculate the area (in2) of the triangular-shaped pieces of sheet metal in Figure 46. NOTES Figure 46 11. Find the area (cm2) of a circle with a diameter of 650 mm, rounded to two decimal places. (Use π button). 12. Calculate the area (in2) of the shaded portion of the steel spacer plate in Figure 47, rounded to three decimals. (Use π button) Figure 47 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 33 NOTES 13. Calculate the area (ift2) of the piece of sheet metal in Figure 48. Figure 48 14. Find the area (in2) of the stair stringer support plate in Figure 49. Figure 49 15. How many square feet of 58" steel plate do you require for a highway bridge surface if you need 375 sections of the shape in Figure 50 to complete the job? Figure 50 34 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 16. Find the lateral surface area (ft2) and rounded to two decimal places of a cylinder if the diameter is 32" and the height is 8.6'. (Use π button). NOTES 17. Find the total surface area (ft2) and rounded to two decimal places of an enclosed cylinder if the diameter is 53" and the height is 4.5'. (Use π button). 18. Determine the lateral surface area (in2) of the steel tank in Figure 51. Figure 51 Volume 1. Define volume. 2. What formula do you use to find the volume of a right rectangular solid? 3. You use the formula V = r2h to find the volume of what figure? 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 35 NOTES 4. Convert each of the following volumes. Round your answers to two decimal places where applicable. a) 2 ft3 to in3 b) 123 ft3 to in3 c) 3.65 ft3 to in3 d) 3466 in3 to ft3 e) 18.144 in3 to ft3 f) 2946 in3 to ft3 and yd3 g) 3912 ft3 to yd3 5. What is the volume (in3) of the three steel bars in Figure 52? (Round your answers to two decimal places where applicable.) a) A = b) B = c) C = Figure 52 36 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 6. The two tanks in Figure 53 are made from 14 gauge steel plate. Determine the volume of tank A (in3) and the volume of tank B (ft3). Round your answers to two decimal places. NOTES Figure 53 3 7. Find the volume of a cylinder (ft ), rounded to two decimal places, if the diameter is 24" and the height is 200'. (Use π button). 8. What is the volume (ft3), (rounded to two decimal places, of the hot water tank in Figure 54? (Use π button). Figure 54 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 37 NOTES 9. Three cylindrical coolant tanks are welded together (Figure 55). What is the volume (ft3), rounded to two decimal places, if you fill the system and connecting pipe completely? (Use π button). Figure 55 3 3 10. Calculate the volume (in ) and (ft ) of the heavy equipment fuel tank in Figure 56, rounded to two decimal places. (Use π button). Figure 56 38 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES Objective Three When you have completed this objective, you will be able to: Calculate the weight of a solid. Calculating the Weight of a Solid In order to calculate the mass or weight of an object, you must first find its volume. You then multiply the volume by the known weight of one unit of volume of the material in question. In the metric system, the weight of one cubic centimetre of steel is 7.849 grams. In the imperial system, the weight of one cubic inch of steel is 0.2835 lb. Example 1 Find the weight (grams and kg) of the round bar in Figure 57, rounded to the nearest tenth. Figure 57 - Solid round bar. To solve, follow these steps. 1. Find the volume. V r 2 h V 152 100 V 70 686.83471 cm3 NOTE For accuracy, do not round any number until you complete your last calculation. Leave 70 686.83471 in the calculator display as you proceed to calculate the weight. 2. Multiply volume by 7.849 g/cm3 to find the weight. Weight 70 686.83471 cm 3 7.849 g / cm 3 The weight for the solid round bar in Figure 57 in grams is 554 813.1 g (rounded) and in kilograms is 554.8 kg (rounded). 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 39 NOTES Example 2 Find the weight (lb) of the rectangular bar in Figure 58, rounded to the nearest tenth. Figure 58 - Solid rectangular bar. To solve, follow these steps. 1. Find the volume in cubic inches. V LWH V 72" 3" 2" V 432 in 3 2. Multiply the volume by 0.2835 lb/in3 to find the weight. Weight 432 in 3 0.2835 lb / in 3 The weight for the solid rectangular bar in Figure 58 is 122.5 lb. NOTE You can calculate the weight of any solid if you know the volume and if you know the weight of one unit of volume of the material. 40 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES Example 3 Calculate the weight (lb) of the solid steel in Figure 59. For this example, use π = 3.14. The weight of one cubic inch of steel is 0.2835 lb/in3. Figure 59 - Calculating the weight of a solid. To solve for Example 3, do the following. Weight Area of Base Height 0.2835 lb / in 3 Weight (1 / 2 r 2 LW 1 / 2 bh) H 0.2835 Weight [(1 / 2 ) 3.14 22 6 4 (1 / 2 5 4)] 8 0.2835 Weight 6.28 24 10 8 0.2835 Weight 40.28 8 0.2835 The weight is 91.36 lb. NOTE Ensure that you use the correct measurements in your formulas. In this example, h = 4" is the height when you calculate the area of the triangle; however, H = 8" is the height of the solid when you calculate the volume. You may want to use altitude instead of height when dealing with triangles to avoid confusion. 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 41 NOTES Objective Three Exercise 1. Describe the procedure for calculating the weight of a solid. 2. Find the weight (lb) of a 20' long piece of 118" diameter steel shaft, rounded to two decimal places. (Use the button). 3. Find the weight (grams and kilograms) of the piece of steel shaft in Figure 60 and round to the nearest tenth. (Use button) Figure 60 4. You must field erect an enclosed oil storage tank 60'in diameter and 25' high at an oil company battery site. The weight of the tank’s 38" sheet steel is 15.3 lbs/ft2. Find the total weight of the tank (rounded to two decimal places) if you use an extra 756 lb for bracing material. (Use the button). 5. Find the weight (kg) of a steel plate if the plate measures 3 m long, 30 cm wide and 30 mm thick. Round your answer to two decimal places. 42 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 6. What is the weight (lb) of the solid bar of aluminum in Figure 61, rounded to two decimal places? Aluminum weighs 0.093 lb/in3. NOTES Figure 61 7. Calculate the weight (lb) of the cast iron overhead crane counterweight in Figure 62, rounded to two decimal places. Cast iron weighs 475 lb/ft3. Figure 62 8. Determine the weight (lb) of the iron casting in Figure 63, rounded to two decimal places. Cast iron weighs 475 lb/ft3. Figure 63 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 43 NOTES 9. Find the total weight (kg) of the steel column support gussets in Figure 64, if you have to fabricate 52 gussets. Round your answer to three decimal places. Figure 64 10. Find the weight (lb) of the steel roller shaft support in Figure 65. Round your answer to three decimal places. (Use button). Figure 65 44 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES Objective Four When you have completed this objective, you will be able to: Calculate the capacity of a container in gallons and litres. Capacity of an Object To find the capacity of an object, you must first find the volume and then convert from cubic measure into gallons (imperial measurement) or litres (metric measurement). Some of the basic relationships that you must know are as follows. 1 imperial gallon = 277 in3 (approximately) 1 ft3 = 6.239 imperial gallons (approximately) 1 ft3 = 1728 in3 1 yd3 = 27 ft3 1 ml = 1 cm3 1 litre (L) = 1000 millilitres (mL) 1 L = 1000 cubic centimetres 1 cubic metre = 1000 litres Example 1 What is the capacity (gallons) of the tank in Figure 66? The volume of the tank is 7.5 ft3 or 12 960 in3. Figure 66 - Finding the capacity of a rectangular tank. To solve for Example 1, you can either multiply 7.5 ft3 by 6.239 galft3 to equal 46.8 gallons (rounded) or divide 12 960 in3 by 277 in3gal to equal 46.8 gallons (rounded). 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 45 NOTES Example 2 What is the capacity (gallons) of the tank in Figure 67? The volume of the tank is 679.93 ft3. Figure 67 - Finding the capacity of a semicircular tank. To solve for Example 2, you multiply 679.93 ft3 by 6.239 gal/ft3 to equal 4242.08 gallons (rounded). Example 3 What is the capacity (litres) of the tank in Figure 68? The volume of the tank is 392.6990817 cubic metres (392 699 081.7 cubic centimetres). Round your answer to the nearest tenth. Figure 68 - Finding the capacity of a circular holding tank. To solve for Example 3, you can multiply 392.6990817 m3 by 1000 L/m3 to equal 392 699.1 L or divide 392699081.7 cm3 by 1000 cm3/L to equal 392 699.1 L. 46 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES Objective Four Exercise 1. Describe the procedure for finding the capacity of an object. 2. Find the number of gallons that the hydraulic oil reservoir tank in Figure 69 can hold. Round your answer to two decimal places. Figure 69 3. What is the capacity (litres) of a rectangular tank that is 3.25 m long, 92.75 cm wide and 190 mm high? Round to one decimal place. 4. A saddle tank for a delivery truck has the same dimensions as Figure 70. Determine the number of gallons that the tank can hold and round to two decimal places. Figure 70 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 47 NOTES 5. What is the capacity (gallons) and rounded to one decimal place, of a cylindrical tank that is 5' in diameter and 5' high? (Use button). 6. What is the capacity (gallons) of the cylindrical steel tank in Figure 71? Round your answer to two decimal places. (Use button) Figure 71 7. How many gallons are in the semicircular ended tank in Figure 72, if you fill it to a height of 212' ? Round your answer to two decimal places. (Use button) Figure 72 48 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 8. A circular stainless steel tank has a diameter of 3 m and you fill it with gasoline to a depth of 450 cm. If you lower the depth by 2 m, how many litres of gasoline did you draw off, rounded to two decimal places? (Use button) NOTES 9. The fuel tank in Figure 73 fits onto a piece of heavy equipment. Determine its capacity (gallons) and round your answer to two decimal places. (Use button) Figure 73 10. Calculate the capacity (gallons) of the coolant reservoir tank and manifold system in Figure 74. Round your answer to two decimal places. (Use button) Figure 74 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 49 NOTES Self-Test 1. Which statement is an equation? a) 2r2 + dh b) 2LW + 2LH + 2WH c) h[(B+b)/2] d) C = d 2. What is the definition of a formula? a) a law or rule that you express as an equation b) a numerical value in a term c) an unknown quantity in a term d) a replacement for a variable 3. An unchanging numerical value that forms part of an equation or formula is a(n): a) variable. b) constant. c) solution. d) unknown. 4. A symbol that represents the unknown quantity in an equation or formula is a: a) solution. b) constant. c) variable. d) law or rule. 5. What is the solution for the formula n = 9 – 2 x 4 + 12 8? a) n = 2.5 b) n = 3.5 c) n = 5 d) n = 29.5 6. What is the perimeter of a square if the length of each side is 812"? a) 72.25" b) 34" c) 32" d) 17" 7. What is the perimeter of a rectangle if the width is 3" and the length is four times the width? a) 14" b) 15" c) 24" d) 30" 50 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 8. What is the perimeter of a triangle if the lengths of the sides are 1958", 22916" and 27132"? a) 681532" b) 5' 9732" c) 6' 9732" d) 68932" NOTES 9. Calculate the circumference of a 25' diameter tank, rounded to two decimal places. a) 39.27' b) 78.54' c) 157.08' d) 490.87' 10. Calculate the area (square inches) of a tank lid that is 2' in diameter. Round to the nearest tenth. a) 37.7 in2 b) 75.4 in2 c) 452.4 in2 d) 1809.6 in2 11. What is the area of a square that measures 30" on each side? a) 6.25 ft2 b) 62.5 ft2 c) 625 ft2 d) 900 ft2 12. What is the area of a rectangle if the length is 28" and the width is 14 of the length? a) 49 in2 b) 70 in2 c) 112 in2 d) 196 in2 13. You cut a triangular piece of steel off the corner of a large square sheet. What is the area of the triangular shaped piece if you measured 2' along one side and 39" along the other side? a) 3.9 ft2 b) 6.3 ft2 c) 468 in2 d) 936 in2 51 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES 14. What is the area (mm2) of the trapezoid in Figure 75? a) 54 mm2 b) 75 mm2 c) 87.5 mm2 d) 112.5 mm2 Figure 75 2 15. What is the area (cm ) of the parallelogram in Figure 76? a) 377 cm2 b) 435 cm2 c) 812 cm2 d) 841 cm2 Figure 76 16. What is the lateral surface area of a piece of pipe with an outside diameter of 10" and a length of 10', rounded to the nearest tenth? a) 314.2 in2 b) 785.4 in2 c) 1885.0 in2 d) 3769.9 in2 17. What is the total surface area of a closed cylindrical tank that measures 3' in diameter and is 36" high? Round to the nearest tenth. a) 42.4 ft2 b) 35.3 ft2 c) 28.3 ft2 d) 14.1 ft2 52 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta 18. What is the volume of a flat bar that measures 34" by 512" and is 20' long? a) 82.5 in3 b) 180 in3 c) 990 in3 d) 1320 in3 NOTES 19. Calculate the volume of a piece of 118" diameter cold rolled steel that is 12' long Round to the nearest tenth. a) 572.6 in3 b) 143.1 in3 c) 508.9 in3 d) 11.9 in3 20. What is the capacity in gallons (1 gal = 277 cubic inches) of a rectangular tank that measures 20" by 32" and is 114' high? Round to the nearest tenth. a) 1538.7 gal b) 800 gal c) 128.2 gal d) 34.7 gal 21. Calculate the capacity in gallons (1 cubic foot = 6.239 gal) of a tank with a diameter of 8' and a height of 16'. Round to the nearest tenth. a) 5017.7 gal b) 3217.0 gal c) 2508.9 gal d) 804.2 gal 22. Steel weighs 0.2835 lb/in3. What is the weight of a 12" thick sheet of steel that is 4' wide and 32' long? (Round to the nearest tenth). a) 217.7 lb b) 2612.7 lb c) 4608 lb d) 9216 lb 23. Steel weighs 0.2835 lb/in3. What is the weight of a 1" round steel bar that is 20' long? (Round to the nearest tenth). a) 53.4 lb b) 62.8 lb c) 188.5 lb d) 213.8 lb 53 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES Self-Test Answers 1. d) C = d 2. a) a law or rule that you express as an equation 3. b) constant. 4. c) variable. 5. a) n = 2.5 6. b) 34" 7. d) 30" 8. b) 5' 9732" 9. b) 78.54' 10. c) 452.4 in2 11. a) 6.25 ft2 12. d) 196 in2 13. c) 468 in2 14. b) 75 mm2 15. a) 377 cm2 16. d) 3769.9 in2 17. a) 42.4 ft2 18. c) 990 in2 19. b) 143.1 in3 20. d) 34.7 gal 21. a) 5017.7 gal 22. b) 2612.7 lb 23. a) 53.4 lb 54 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES Objective One Exercise Answers 1. An equation is a statement or mathematical expression that uses an equal sign to indicate that two related quantities have the same value. All equations must be true. 2. A formula is a law or rule that you express as an equation. A formula expresses some fundamental fact or truth. 3. A constant is a numerical value that forms part of an equation or formula and cannot change. An example of a constant is . 4. P = 576.84 5. L = 8 6. A = 38.465 7. A = 45 8. h = 14 9. 4.5 10. h = 3.2 Objective Two Exercise Answers Perimeter 1. Perimeter is the distance around any geometric figure, such as a square, rectangle, triangle, trapezoid, parallelogram, circle or semicircle. When the figure is a circle, the perimeter is the circumference. 2. rectangle 3. C = d or C = 2r 4. 152 mm 5. 10' 9". 6. 12.6 m 7. 819.2 cm 8. 128' 211/16" 9. 23.1 cm 10. a) b) c) d) e) 4363/64" 7525/64" 2027/64" 40' 103/32" 831/4" 11. 36' 31/8" 12. 1032' 13. 1443' 515/16" 14. 11763/64" 55 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES Area 1. Area is the amount of material it takes to cover a surface. 2. A = 12bh 3. square 4. 4 surfaces 5. TSA = dh + 2(r2) 6. a) b) c) d) 4058 in2 8218 in2 162916 in2 614 in2 7. 51 984 ft2 8. $450.00 9. 1 ft2 10. a) b) c) d) 32 in2 45 in2 72 in2 66.5in2 11. 3318.31 cm2 12. 1.575 in2 13. 1.91 6 ft2 14. 10.68 in2 15. 78 000 ft2 16. 72.05 ft2 17. 93.08 ft2 18. 608 in2 Volume 1. Volume is the amount of space that an object occupies. 2. V = LWH 3. volume of a cylinder 4. a) b) c) d) e) f) g) 3456 in3 2880 in3 6307.2 in3 2.01 ft3 0.01 ft3 1.7 ft3; 0.06 yd3 1.46 yd3 56 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES 5. a) 226.88 in3 b) 294 in3 c) 324 in3 6. a) 1199.46 in3 b) 5.36 ft3 7. 628.32 ft3 8. 31.01 ft3 9. 115.56 ft3 10. 58.18 ft3, 100 531.34 in3 Objective Three Exercise Answers 1. In order to calculate the mass or weight of an object, you must first find its volume. You then multiply the volume by the known weight of one unit of volume of the material in question. 2. 67.63 lb 3. 389 010.3 grams or389.0 kg 4. 159 375.01 lb 5. 211.92 kg 6. 6.28 lb 7. 396.93 lb 8. 164.93 lb 9. 179.585 kg 10. 48.476 lb Objective Four Exercise Answers 1. To find the capacity of an object, you must first find the volume and then convert from cubic measure into gallons (imperial measurement) or litres (metric measurement). 2. 131.22 gallons 3. 572.7 litres 4. 77.98 gallons 5. 612.5 gallons 6. 640.27 gallons 7. 142.57 gallons 8. 14 137.17 litres 9. 212.39 gallons 10. 61.35 gallons 57 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta NOTES 58 120104dp7.0.docx © 2014, Her Majesty the Queen in right of the Province of Alberta Module Number 120104d Version 7.0
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