MathMaster Blog

A sphere is a set of points in space that are a given distance r from the center.

The formula of the surface area of the sphere depends on the radius of the sphere.

Surface Area of Sphere = 4πr^2

In terms of diameter, the surface area of a sphere is expressed as:

S = 4π(d/2)^2

Example 1:

A ball has a diameter of 34.4 m. Calculate the amount of material required to cover the ball. Round to the nearest tenth of a square meter.

Solution:

As the radius is (34.4/2) = 17.2 m , surface area is 4 x (22/7) x (17.2)^2.

=> Area = 3719.13 m^2

Answer: The material required is 3719.13 square meters.

Example 2:

Find the surface area of a sphere with a radius of 20 ft. (Use = 3.14)

Solution:

The surface area of the sphere = 4πr^2 = 4 x π x 20^2 = 5024 feet^2.

Answer: 5024 feet^2