Sphere

A sphere is a three dimensional version of a circle, like a basketball or a marble. The definition of a sphere is "every point that is the same distance from a single point called the center."

The diameter of a sphere:

The line passing through the center from one end to the other called the diameter of the sphere. The diameter of the sphere denoted as D.

Diameter = 2 times radius of the sphere

D = 2 × r

Circumference of a sphere:

Circumference of a sphere is the distance covered around the sphere. The unit of the circumference is the same as the radius.

Circumference = 2×π×r

The surface area of a sphere:

The surface area of a sphere is the number of square units that will exactly cover the surface of a sphere. The unit of the surface area of sphere is a square unit m²

Surface Area of sphere =4×π×r²

Example:

Determine the surface area of a sphere having a radius of 7 cm

Solution:

SA = 4× (22/7)× 7²

= 4 × 22 × 7

= 616 cm²

The volume of a sphere:

The surface area of a sphere is the number of square units that will exactly cover the surface of a sphere. The unit of the surface area of sphere is a square unit m²

Volume of sphere = 4/3(πr³)

Example:

Find the volume of the sphere that has a radius of 5 cm?

Solution:

V = (4/3)× (22/7) ×5³

= 522 cm³