[tex]\bf \textit{circumference of a circle}\\\\ C=2\pi r~~ \begin{cases} r=radius\\ \cline{1-1} C=32 \end{cases}\implies 32=2\pi r\implies \cfrac{32}{2\pi }=r \\\\\\ \cfrac{16}{\pi }=r\implies 5.092958178940651\approx r\implies \stackrel{\textit{rounded up}}{5.1=r}[/tex]
