[tex]\bf \textit{area of a sector of a circle}\\\\
A=\cfrac{\theta \pi r^2}{360}\quad
\begin{cases}
r=radius\\
\theta =angle~in\\
\qquad degrees\\
------\\
r=24\\
A=90
\end{cases}\implies 90=\cfrac{\theta \pi 24^2}{360}\implies 90=\cfrac{\theta \pi 576}{360}
\\\\\\
90=\cfrac{8\theta \pi }{5}\implies 450=8\theta \pi \implies \cfrac{450}{8\pi }=\theta \implies \cfrac{225}{4\pi }=\theta \\\\\\ 17.904931 \approx \theta [/tex]