Question

If the radius and slant height of a right circular cone are $4$ cm and $7$ cm respectively, then its curved surface area will be:

• A. $78c{m}^2$
• B. $87c{m}^2$
• C. $88c{m}^2$
• D. $74c{m}^2$

Answer 1

The correct option is C $88c{m}^2$

Given,
Radius of the cone $=4$ cm
and Slant height of the cone $=7$ cm.

We know, the curved surface area of a cone $=\pi rl$
$=\frac{22}{7}\times 4\times 7$
$=88c{m}^2$.

Therefore, option $C$ is correct.