[tex]\bf \textit{area of a circle}\\\\ A=\pi r^2~~ \begin{cases} r=radius\\ \cline{1-1} A=676\pi \end{cases}\implies 676\pi =\pi r^2\implies \cfrac{676\pi }{\pi }=r^2 \\\\\\ 676=r^2\implies \sqrt{676}=r\implies 26=r~\hspace{10em}\stackrel{\textit{diameter = 2r}}{52}[/tex]
