Question

Find the surface area of a right circular cone whose height is 12m and radius is 15m.

Answer 1

Use the formula 2pi(radius)(height)+2pi(r)^2

Answer 2

surface area = πr^2 + πrl = πr[r + l]

for finding l use the formula l = sqrt(h^2 + r^2)
so l = sqrt(12^2 + 15^2) = sqrt(144 + 225) = sqrt(369) = 19.21

using π = 3.14

surface area = 3.14*15m [15m + 19.21m]
= 3.14*15m*34.21m
= 1611.29 m^2