Respuesta :

[tex] \bf \textit{area of a circle}\\\\
A=\pi r^2~~
\begin{cases}
r=radius\\[-0.5em]
\hrulefill\\
A=32.1
\end{cases}\implies 32.1=\pi r^2\implies \cfrac{32.1}{\pi }=r
\\\\\\
\sqrt{\cfrac{32.1}{\pi }}=r\implies 3.19652113187\approx r [/tex]