MathMaster Blog

The overall surface area of a cylinder includes the area of the curving surface as well as the area of a cylinder's two circle-shaped bases.

Surface area is measured in square millimeters, square inches, square feet, and other similar units.

So, the total surface area of a cylinder = 2πr(r + h), where:

r = radius of the cylinder

h = height of the cylinder

Example 1:

Calculate the area of a cylinder with a radius of 5 inches and a height of 15 inches. Take the value of pi as 3.14.

Solution:

Radius, r = 5 in

Height of the cylinder, h = 15 in

The surface area of the cylinder is:

A = 2πr(r+h)

= 2π × 5 × (5 + 15)

= 2π × 5 × 20

= 2 × 3.14 × 5 × 20

= 628

Answer: The surface area of the cylinder is 628 square inches.

Example 2:

The area of the cylinder is 500 cm² and its height is 10 cm. Find the radius of its base.

Solution:

The lateral surface area is A =2πrh. The curved surface area is A = 500 cm² and its height is 10 cm, hence:

A = 2πrh

500 = 2 × 3.14 × r × 10

500 = 62.8r

r = 500/62.8

= 7.96

Answer: The radius of the base is 7.96.