JAMB 2002 · UME · Q16

A solid hemisphere has radius 7 cm. Find its total surface area. $\left[\pi = \frac{22}{7}\right]$

Worked solution (try it first)

A solid hemisphere has a curved surface, half of $4\pi r^2$ , which is $2\pi r^2$ , plus a flat circle $\pi r^2$ .
Together that is $3\pi r^2$ .
$3 \times \frac{22}{7} \times 49 = 3 \times 154$
$= 462\text{ cm}^2$ , option A.