Question

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

`["Assume "pi=22/7]`

 

Answer 1

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

Slant height (l) of cone = 21 m

Total surface area of cone = πr(r + l)

= `[22/7xx12xx(12+21)]  m^2`

= `(22/7xx12xx33)  m^2`

= `8712/7  m^2`

= 1244.57 m²