The image above is a conical frustum.

To compute the lateral surface area of a conical frustum requires three essential parameters which are the radius of the lower base (R), radius of the upper base (r) and the height (h).

The formula for calculating the lateral surface area of a conical frustum:

A = π(R + r)√((R – r)² + h²)

Where;

A = Area of the conical frustum

R = Radius of the lower base

r = Radius of the upper base

h = Height of the conical frustum

Let’s solve an example;

Given that the height of a conical frustum is 28 cm with a radius of lower base of 22 cm and a radius of upper base of 19 cm. Find the lateral surface area of the conical frustum?

This implies that;

h = Height of the conical frustum = 28 cm

R = Radius of the lower base = 22 cm

r = Radius of the upper base = 19 cm

A = π(R + r)√((R – r)² + h²)

A = 3.142(22 + 19)√((22 – 19)² + 28²)

A = 3.142(41)√((3)² + 28²)

A = 3.142 (41)√(9 + 784)

A = 3.142 (41)√(793)

A = 3.142 (41)(28.16)

A = 3.142 x 1154.56

A = 3627.63

Therefore, the** lateral surface area of the conical frustum** is **3627.63 cm².**