Respuesta :

[tex]\bf \textit{area of a circle}\\\\ A=\pi r^2~~ \begin{cases} r=radius\\[-0.5em] \hrulefill\\ A=64\pi \end{cases}\implies 64\pi =\pi r^2 \implies \cfrac{64\pi }{\pi }=r^2 \\\\\\ 64=r^2\implies \sqrt{64}=r\implies 8=r[/tex]