Spheres

A sphere is the set of all points that are a fixed distance from a given point called the center.

A radius of a sphere is a segment whose endpoints are the center and a point on the sphere.

A diameter of a sphere is a segment that joins two points on the sphere and passes through its center.

A tangent to a sphere is a line that intersects the sphere at exactly one point.

A chord of a segment whose endpoints are points on the sphere.

Surface Area of a Sphere: If a sphere has a surface area of S square units and a radius of r units, then S = 4πr².

Volume of a Sphere: If a sphere has a volume of V cubic units and a radius of r units, then V = 4/3 πr³.

Find out more about the surface areas and volumes of spheres by reading the explanation below.

Practice: Find the surface areas and volumes of spheres in the following exercises.