Question

The slant height of a right circular cone is 10 m and its height is 8 m. Find the area of its curved surface. (in $m^2$)

• A.
• B.
• C.
• D.

Answer 1

The correct option is C

$l=10m,h=8m$

Since height, radius and slant height makes a right angle triangle,
$So,r^2=l^2-h^2{r}^2={10}^2-8^2=100-64=36r=6m$
Curved surface area = $\pi rl=(\pi \times 6\times 10)m^2=60\pi m^2$