Answer:
12.56 square cm
Step-by-step explanation:
Radius of bigger semicircle R= 4 cm
Radius of one smaller semicircle r = 2 cm
Area of shaded portion = Area of bigger semicircle - 2 times area of one smaller semicircle.
[tex] = \frac{1}{2} \pi {R}^{2} - 2 \times \frac{1}{2} \pi {r}^{2} \\ \\ = \frac{1}{2} \pi {R}^{2} - \pi {r}^{2} \\ \\ = \pi( \frac{1}{2} \times {R}^{2} - {r}^{2}) \\ \\ = \pi( \frac{1}{2} \times {4}^{2} - {2}^{2} ) \\ \\ = \pi( \frac{1}{2} \times 16 - 4) \\ \\ = \pi(8 - 4) \\ = 3.14 \times 4 \\ = 12.56 \: {cm}^{2} \\ [/tex]
