## Basic College Mathematics (9th Edition)

The area of the shaded region: 57 cm$^{2}$
To find the area of the shaded region simply find the area of the semicircle and subtract the area of the triangle. Area of a Semicircle: $A$$_{semi} = \pi$$r$$^{2} / 2 Therefore: A$$_{semi}$ = (3.14)(10 cm)$^{2}$ / 2 $A$$_{semi} = 157 cm^{2} A$$_{tri}$ = $\frac{1}{2}$$b$$h$ $A$$_{tri} = \frac{1}{2}(20 cm)(10 cm) A$$_{tri}$ = 100 cm$^{2}$ $A$$_{total} = A$$_{semi}$ - $A$$_{tri} A$$_{total}$ = 157 cm$^{2}$ - 100 cm$^{2}$ $A$$_{total}$ = 57 cm$^{2}$