[tex]\textit{area of a circle}\\\\ A=\pi r^2~~ \begin{cases} r=radius\\[-0.5em] \hrulefill\\ A=73 \end{cases}\implies \begin{array}{llll} 73=\pi r^2\implies \cfrac{73}{\pi }=r^2 \\\\\\ \sqrt{\cfrac{73}{\pi }}=r\implies 4.8 \approx r \end{array}[/tex]