[tex]\bf \textit{area of a circle}\\\\
A=\pi r^2\quad
\begin{cases}
r=radius\\
-----\\
A=452.16
\end{cases}\implies 452.16=\pi r^2
\\\\\\
\cfrac{452.16}{\pi }=r^2\implies \sqrt{\cfrac{452.16}{\pi }}=r\implies 11.99695787\approx r[/tex]
now, that's the radius of the circle, recall that the diameter is twice the radius.
