[tex]\bf \textit{area of a circle}\\\\
A=\pi r^2~~
\begin{cases}
r=radius\\
-----\\
A=24\pi
\end{cases}\implies 24\pi =\pi r^2\implies \cfrac{24\pi }{\pi }=r^2
\\\\\\
24=r^2\implies \boxed{\sqrt{24}=r}\\\\
-------------------------------\\\\
\textit{circumference of a circle}\\\\
C=2\pi r\qquad \qquad \implies C=2\pi\left( \boxed{\sqrt{24}} \right)~~
\begin{cases}
24=2\cdot 2\cdot 2\cdot 3\\
\qquad 2^2\cdot 6
\end{cases}
\\\\\\
C=2\pi \sqrt{2^2\cdot 6}\implies C=2\pi (2\sqrt{6})\implies C=4\sqrt{6}~\pi[/tex]
