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An image of a sphere

A sphere is a shape in space that is like the surface of a ball. Most of the time, the terms ball and sphere are used as the same. But in mathematics, the precise (exact) definition only allows points in the 3 dimensional space which are uniformly and symmetrically located at a fixed length called radius of the sphere.

Examples of these are basketballs, superballs, and playground balls.

In other places sphere means the earth.[source?]

A sphere is the 3 dimensional analogue of a circle.

Volume[change | change source]

The volume of a sphere is given by the following formula

\!V = \frac{4}{3}\pi r^3

\pi is a constant that is approximately equal to 3.1416.

Surface Area[change | change source]

Surface area of a sphere

The surface area of a sphere is given by the following formula

\!A =4 \pi r^2