[tex]\textit{surface area of a cylinder}\\\\ SA=2\pi r(h+r)~~ \begin{cases} r=radius\\ h=height\\[-0.5em] \hrulefill\\ r=4\\ h=12 \end{cases}\implies SA=2\pi(4) (12+4) \\\\\\ SA=8\pi (16)\implies SA=128\pi \implies \stackrel{using~\pi =3.14}{SA\approx 401.92}~in^2[/tex]
