[tex]\textit{volume of a cylinder}\\\\ V=\pi r^2 h~~ \begin{cases} r=radius\\ h=height\\[-0.5em] \hrulefill\\ V=10297\\ h=21 \end{cases}\implies 10297=\pi r^2(21)\implies \cfrac{10297}{21\pi }=r^2 \\\\\\ \cfrac{1471}{3\pi }=r^2\implies \sqrt{\cfrac{1471}{3\pi }}=r\implies 12\approx r[/tex]