notice, the circle is missing 1/4, so the area of it is just 3/4 of the whole area of the circle.
[tex]\bf \textit{area of a circle}\\\\ A=\pi r^2~~ \begin{cases} r=radius\\[-0.5em] \hrulefill\\ r=8 \end{cases}\implies A=\pi 8^2\implies A=64\pi \\\\\\ \stackrel{whole}{\cfrac{4}{4}}-\stackrel{one~quarter}{\cfrac{1}{4}}=\cfrac{3}{4}~\hfill \cfrac{3}{4}\cdot 64\pi \implies 48\pi \implies \stackrel{\pi =3.14}{150.72} \\\\\\ ~\hspace{34em}[/tex]
