Question

The curved surface area of a cone of radius $7$ cm and height $24$ cm is:

• A. $440{\text{cm}}^2$
• B. $550{\text{cm}}^2$
• C. $110{\text{cm}}^2$
• D. $330{\text{cm}}^2$

Answer 1

Answer: (B)

Given, Radius of cone, $r=7cm$ and Height, $h=24cm$.

To find slant height $l$:

We know, $l^2=r^2+h^2$

$⟹$ $l^2=7^2+{24}^2$

$⟹$$l^2=625$

$⟹$$l=25cm$.

Therefore, curved surface area of cone is $=\pi rl$

$=\frac{22}{7}\times 7\times 25$

$=22\times 25$

$=550c{m}^2$.

Hence, the curved surface area of cone is $550c{m}^2$.

Thus, option $B$ is correct.