Question

Find the total surface area of a cone, if its slant height is 21 m and diameter of its base is 24 m.

Answer 1

Given that,

Radius of base of cone =` (24/2)` = 12 m

The slant height of the cone = 21 m.

Total surface area of cone = πr² + πrl

= πr (r + l)

= `22/7xx12xx(12+21)  m^2`

= `22/7 xx 12 xx 33  m^2`

= `8712/7  m^2`

= `1244.57  m^2`.