Question

The curved surface area of a cone is $320m^2$ whose radius is $7$ m. Find the surface area of a cone (Assume $\pi =\frac{22}{7}$).

• A. $474m^2$
• B. $424m^2$
• C. $404m^2$
• D. $454m$

Answer 1

The correct option is A $474m^2$

Given, surface area of cone $=320$ $m^2$ and radius $7$ m.

$\therefore$ Total surface area of a cone $=$ $\pi rs+\pi r^2$
$=320+\left(\frac{22}{7}\right)\times 7\times 7$
$=320+154$
$=474m^2$.

Hence, option $A$ is correct.