Unit 4 Chapter 6 Section 4 Area of a Trapezoid and Irregular Figures.notebook
February 29, 2016
If you know how to find the area of simple figures, you can find the
area of irregular figures by "breaking apart" or "completing" the
irregular figure into simple figures.
1
Unit 4 Chapter 6 Section 4 Area of a Trapezoid and Irregular Figures.notebook
February 29, 2016
More Than One Way
Anna and Ryan are helping their friends build a large wooden deck. What is the area of the deck?
15 ft
9 ft
12 ft
12 ft
27 ft
Anna's Method: I'll subtract the area of the triangle from the area of the rectangle.
Area of the rectangle:
Area of the triangle:
15 ft
9 ft
12 ft
12 ft
27 ft
Ryan's Method: I'll add the areas of the rectangle and the trapezoid.
Area of the trapezoid:
Area of the rectangle:
15 ft
9 ft
12 ft
12 ft
27 ft
Choose a Method: With a Partner
Find the area of the figure.
6 m
2 m
3 m
6 m
5 m
16 m
2
Unit 4 Chapter 6 Section 4 Area of a Trapezoid and Irregular Figures.notebook
February 29, 2016
3) Break this figure into other shapes and find the missing measurements. a)
7cm
4 cm
3 cm
4 cm
13 cm
b)
8 ft. 3 ft.
3 ft.
11 ft.
3 ft.
3 ft.
8 ft. 3
Unit 4 Chapter 6 Section 4 Area of a Trapezoid and Irregular Figures.notebook
February 29, 2016
Bell Ringer­ c)
4 mm
6 mm
8 mm
16 mm
d)
2 ft. 4 ft. 12 ft. 11 ft. 8 ft. 5 ft.
4
Unit 4 Chapter 6 Section 4 Area of a Trapezoid and Irregular Figures.notebook
February 29, 2016
Challenge
1) A trapezoid has an area of 184 in2. The height is 8 in and the length of one base is 16 in. Write and solve an equation to find the length of the other base.
4 in
2) Find the area of this figure.
5 in
6 in
5 in
8 in
5
Unit 4 Chapter 6 Section 4 Area of a Trapezoid and Irregular Figures.notebook
February 29, 2016
Closure
1) What is the formula for the area of a trapezoid?
2) Find the area for a trapezoid with b1 = 14 ft, b2 = 8 ft and h = 12 ft.
3) Find the area of each figure.
a)
18.5
cm
b)
6.75 cm
3.25 cm
4 ft
5 ft
16 cm
2 ft
7 ft
6