[tex]\bf \textit{area of a sector of a circle}\\\\
A=\cfrac{\theta\pi r^2}{360}\qquad
\begin{cases}
\theta=\textit{angle in degrees}\\
r=radius\\
----------\\
r=8\\
A=125.6
\end{cases}
\\\\\\
360A=\theta\pi r^2\implies \cfrac{360A}{\pi r^2}=\theta\implies \cfrac{360\cdot 125.6}{\pi 8^2}=\theta[/tex]