Composite Figures

Composite Figures

•A composite figure is made up of two or more shapes. •To find the area of a composite figure, decompose the figure into shapes with areas you know. Then find the sum of these areas.

Example 1

6 m

11 m

This figure can be separated into a semicircle and a parallelogram. To find the area of this composite figure, find the area of the parallelogram, and find the area of the semicircle. Then add the two areas together.

Area of ParallelogramA = b(h)A = 11(6)A = 66m²

Area of Semicircle2

2

1rA

2)3(2

1A

)9(2

1A

...)27433388.28(2

1A

214.1413716694.14 mA

Area of the composite figureArea of parallelogram + area of semicircle66 + 14.14 = 80.14m²The area of the composite figure is 80.14m².

Example 2

This figure can be separated into two parallelograms. To find the area of this composite figure, find the area of the two parallelograms.

Area of the smaller parallelogramA = b(h)A = 7(7)A = 49cm²

Area of the larger parallelogramA = b(h)A = 9 (20)A = 180 cm²

9 cm

20 cm

7 cm

7 cm

Area of the composite figureArea of sm. parallelogram + area of lg. parallelogram49 + 180 = 229 cm²The area of the composite figure is 229 cm².