Area of Circle

Answer: A

\begin{equation*}
\begin{split}
\text{Area of circle}& = \pi \cdot r^2\\\\
\text{Area of circle}& = \frac{22}{7} \cdot 21^2\\\\
\text{Area of circle}& = \frac{22}{\cancel{7}} \cdot \cancelto{3}{21} \cdot 21\\\\
\text{Area of circle}& = 1386 \text{ cm}^2
\end{split}
\end{equation*}