Problems 14-18 from Practice for 0-9, 1-3, 1-6 with Steps
14. Find the perimeter of a square that has area 25 cm2.
(a) Write the formula for area of a square, and substitute the given area into it
(b) Solve.
(c) Write the formula for perimeter of a square, and find the perimeter. Include units with your answer.
15. The length of a rectangle is 5 times its width, and its perimeter is 24 ft. Find the area of the rectangle.
(a) Write an equation describing “the length of a rectangle is 5 times its width.”
(b) Write the formula for perimeter of a rectangle, and substitute the given perimeter into it.
(c) Substitute to combine your equations from (a) and (b), and solve.
(d) Find the length and width of the rectangle.
(e) Write the formula for area of a rectangle, and find the area. Include units with your answer.
16. The length of a rectangle is 3 times its width, and its area is 300 cm2. Find the perimeter of the rectangle.
(a) Write an equation describing “the length of a rectangle is 3 times its width.”
(b) Write the formula for area of a rectangle, and substitute the given area into it.
(c) Substitute to combine your equations from (a) and (b), and solve.
(d) Find the length and width of the rectangle.
(e) Write the formula for perimeter of a rectangle, and find the perimeter. Include units with your answer.
17. The area of a circle is 64 in2. Find the circumference of the circle.
(a) Write the formula for area of a circle, and substitute the given area into it.
(b) Solve.
(c) Write the formula for circumference of a circle, and find the circumference. Include units with your
answer.
18. The circumference of a circle is 100 in. Find the area of the circle.
(a) Write the formula for circumference of a circle, and substitute the given circumference into it.
(b) Solve.
(c) Write the formula for area of a circle, and find the area. Include units with your answer.
Problems 11-15 from Review for 0-9, 1-3, 1-6 with Steps
11. Find the perimeter of a square that has area 36 cm2.
(a) Write the formula for area of a square, and substitute the given area into it.
(b) Solve.
(c) Write the formula for perimeter of a square, and find the perimeter. Include units with your answer.
12. The length of a rectangle is 4 times its width, and its perimeter is 20 ft. Find the area of the rectangle.
(a) Write an equation describing “the length of a rectangle is 4 times its width.”
(b) Write the formula for perimeter of a rectangle, and substitute the given perimeter into it.
(c) Substitute to combine the equations in (a) and (b), and solve.
(d) Find the length and width of the rectangle.
(e) Write the formula for area of a rectangle, and find the area. Include units with your answer.
13. The length of a rectangle is 2 times its width, and its area is 162 cm2. Find the perimeter of the rectangle.
(a) Write an equation describing “the length of a rectangle is 2 times its width.”
(b) Write the formula for area of a rectangle, and substitute the given area into it.
(c) Substitute to combine your equations from (a) and (b), and solve.
(d) Find the length and width of the rectangle.
(e) Write the formula for perimeter of a rectangle, and find the perimeter. Include units with your answer.
14. The area of a circle is 144 in2. Find the circumference of the circle.
(a) Write the formula for area of a circle, and substitute the given area into it.
(b) Solve.
(c) Write the formula for circumference of a circle, and find the circumference. Include units with your
answer.
15. The circumference of a circle is 36 in. Find the area of the circle.
(a) Write the formula for circumference of a circle, and substitute the given circumference into it.
(b) Solve.
(c) Write the formula for area of a circle, and find the area. Include units with your answer.