Answer
The area of the shaded region: 57 cm$^{2}$
Work Step by Step
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$^{2}$
