area-and-perimeter-of-circle-problem-solving-03

Answer: C

\begin{equation*}
\begin{split}
\text{Perimeter of the shaded region} &= \text{circumference of semicircle}\\\\
\text{Perimeter of the shaded region} & = \frac{1}{2}\times 2\pi r\\\\
\text{Perimeter of the shaded region} & = \frac{1}{\cancel{2}}\cdot \cancel{2}\cdot \frac{22}{\cancel{7}} \cdot \cancel{7}\text{ cm}\\\\
\text{Perimeter of the shaded region} & = 22 \text{ cm}
\end{split}
\end{equation*}