If the height and slant height of a cone are 21cm and 28cm respectively. Find its volume.

Explanation

given that `h=21cm` & `l=28cm`

so `r=(l^2-h^2)^(1/2)`

`r=(28^2-21^2)^(1/2)`

`r=7(7)^(1/2)`

so volume `=(1/3)pi(r^2)h`

`=(1/3)pi[{7(7)^(1/2)}^2]21`

`=6746cm^3`