Question

A cone has a circular base with a diameter of 18 inches the height of the cone is 40inches what is the approximate lateral area of the cone

Answer 1

`A=1158.66\ \text{inches}^2`

Explanation:

Given that,

The diameter of the base of a circular cone, d = 18 inches

Height of the cone, h = 40 inches

We need to find the lateral surface area of the cone. The formula of the lateral surface of the cone is given by :

`A=\pi rl`

l is the slant height of the cone,

`l=√(r^2+h^2) \\\\l=√((9)^2+(40)^2) \\\\l=41\ \text{inches}`, d = 18 inches, r = 9 inches

So,

`A=3.14* 9* 41\\\\A=1158.66\ \text{inches}^2`

So, the lateral surface area of the cone is
`1158.66\ \text{inches}^2`.