Question

The area of the curved surface of a cone of radius 2r and slant height $\frac{l}{2}$,is

• A. $\pi rl$
• B. $2\pi rl$
• C. $\frac{l}{2}\pi rl$
• D. $\pi (r+l)r$

Answer 1

The correct option is A

$\pi rl$

Radius of a cone =2r

and slant height (l)=$\frac{l}{2}$

Curved surface area=$\pi \left(2r\right)\times \frac{l}{2}=\pi rl$