Question

In pottery class Felix made a 14-in.-high cylindrical vase with a 5-in. radius of the base. He wants to paint the outside of the vase. How many square inches will Felix have to paint? Round to the nearest whole number.

Answer 1

since the vase will  be holding something, and sitting on some surface, Felix will only need to paint the sides of the vase, thus

$\bf \textit{lateral surface area of a cylinder}\\\\ S=2\pi r h~~ \begin{cases} r=radius\\ h=height\\ -----\\ r=5\\ h=14 \end{cases}\implies S=2\pi (5)(14)\implies S=140\pi$