In general, the area of a circle is given by the formula shwn below
[tex]\begin{gathered} A=\pi r^2 \\ r\rightarrow\text{ radius} \end{gathered}[/tex]In our case, A=508 m^2; then,
[tex]508=\pi r^2[/tex]Solving for r,
[tex]\begin{gathered} \Rightarrow r=\sqrt{\frac{508}{\pi}} \\ \Rightarrow r\approx12.716 \\ \Rightarrow r\approx12.72 \end{gathered}[/tex]