Unit 4 Chapter 6 Section 4 Area of a Trapezoid and Irregular Figures.notebookMarch 03, 2015
Bellringer:
1) Find the area of the triangle.
9.4 ft
5 ft
5.1 ft
7 ft
2) Find the area of a triangle with a base and height that are twice as long as those in the triangle above.
Unit 4 Chapter 6 Section 4 Area of a Trapezoid and Irregular Figures.notebookMarch 03, 2015
Unit 4
Chapter 6 Section 4
Area of a Other Figures
Objective: To find the area of a trapezoid and the areas of irregular figures
Trapezoid: quadrilateral with one pair of parallel sides
b1 = base 1 of trapezoid
b2 = base 2 of trapezoid
h = height of trapezoid
Area of a Trapezoid: A = 1 h(b1 + b2)
2
Unit 4 Chapter 6 Section 4 Area of a Trapezoid and Irregular Figures.notebookMarch 03, 2015
Examples:
Finding the Area of a Trapezoid
1) Find the area and perimeter of each trapezoid
a)
m
33 c
m
33 c
32 cm
n. 13 i
b)
30 cm
22 in.
15 in.
12 in. 36 cm
13 i
n. area = area = perimeter = perimeter = 2) Find area of each trapezoid.
a) b1 = 11 in
b2 = 16 in
h = 9 in
b) b1 = 3.5 ft
b2 = 2.25 ft h = 2 ft
Unit 4 Chapter 6 Section 4 Area of a Trapezoid and Irregular Figures.notebookMarch 03, 2015
Find the height of a trapezoid if the area is
27cm2 and the two bases are 4cm and 5cm.
Unit 4 Chapter 6 Section 4 Area of a Trapezoid and Irregular Figures.notebookMarch 03, 2015
Homework
Practice Worksheet 6­4
#'s 1 ­ 6, 11