JAMB 1991 · UME · Q45

Find the total surface area of a solid cylinder whose base radius is 4 cm and height is 5 cm.

Worked solution (try it first)

A solid cylinder has a curved surface $2\pi rh$ and two circular ends $2\pi r^2$ : a total of $2\pi r(r + h)$ .
$2\pi \times 4 \times (4 + 5) = 72\pi\text{ cm}^2$ , option B.