Question

A cone has a radius of 12 inches and a slant height of 20 inches. What is the approximate surface area of the cone?

Answer 1

2009.6 in²

Explanation:

The surface area, SA of a cone is obtained using the formular :

SA = πr² + πrl

Where ; r = Radius = 20 inches ; l = slant height = 12 inches

SA = π*20² + π*20*12

SA = 400π + 240π

Take π = 3.14

SA = (400*3.14) + (240*3.14)

SA = 1256 + 753.6

SA = 2009.6 in²