Question

Diameter of the base of a cone is $10.5cm$ and its slant height is $10cm$. Find its curved surface area. $[Assume\pi =\frac{22}{7}]$

Answer 1

Radius $\left(r\right)$ of the base of the cone $=\left(\frac{10.5}{2}\right)cm=5.25cm$
Slant height $\left(l\right)$ of the cone $=10cm$
CSA of cone =$\pi rl$
$=(\frac{22}{7}\times 5.25\times 10)c{m}^2=(22\times 0.75\times 10)c{m}^2=165c{m}^2$