[tex]\bf \textit{area of a sector of a circle}\\\\
A=\cfrac{\theta \pi r^2}{360}~~
\begin{cases}
r=radius\\
\theta =angle~in\\
\qquad degrees\\
------\\
r=5\\
\theta =225
\end{cases}\implies A=\cfrac{(225)(\pi )(5)}{360}\implies A=\cfrac{25\pi }{8}[/tex]
