composite figures. a composite figure is made up of two or more shapes. to find the area of a...
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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.