Question

Diameter of the base of a cone is 10.5 cm and its slant height is 10 cm. Find its curved surface area.

Answer 1

Given that, the diameter of the base of a cone, $d=10.5cm$

Slant height, $l=10cm$

To find out: Curved surface area of the cone.
$r=\frac{d}{2}=\frac{10.5}{2}$

$=5.25cm$

$l=10cm$

We know that, CSA of cone $=\pi rl$

$\Rightarrow \frac{22}{7}\times 5.25\times 10c{m}^2[\because \pi =\frac{22}{7}]$

$=22\times 0.75\times 10c{m}^2$

$=165c{m}^2$

Hence, the curved surface area of the given cone is $165c{m}^2$.