Answer :
[tex]\bf \textit{area of a sector of a circle}\\\\
A=\cfrac{\theta\pi r^2}{360}\qquad
\begin{cases}
r=radius\\
\theta=\textit{angle in degrees}\\
----------\\
r=10\\
\theta=30
\end{cases}\implies A=\cfrac{30\cdot \pi \cdot 10^2}{360}[/tex]