How do you find the surface area of a cone?

Answer 1

A cone has two surfaces, lateral surface and its circular surface at the base.

The surface area of a cone is the sum of the areas of these two surfaces, i.e. (1) area of the lateral surface and (2) area of its base.

Let us consider a right circular cone to find its surface area.

The lateral surface area of a right circular cone is π r l

where,

r is the radius of the circle at the bottom of the cone, and

l is the lateral height of the cone

The surface area of the bottom circle of a cone is the same as for any circle, π r2

Thus the total surface area of a right circular cone is: π r l + πr2 OR π r (l + r)