en.wikipedia.org/wiki/Sphere

A **sphere** is a perfectly round geometrical object in three-dimensional space that
is the surface of a completely round ball Like ...

www.khanacademy.org/math/basic-geo/basic-geo-volume-sa/volume-cones/v/volume-of-a-sphere

The formula for the **volume of a sphere** is V = 4/3 πr³. See the formula used in an
example where we are given the diameter of the sphere.

www.mathopenref.com/spherevolume.html

Animated demonstration of the **sphere volume** calculation.

www.varsitytutors.com/hotmath/hotmath_help/topics/volume-of-a-sphere

A **sphere** is a set of points in space that are a given distance r from the center.
The **volume** of a 3 -dimensional solid is the amount of space it occupies. **Volume**
is ...

www.virtualnerd.com/pre-algebra/perimeter-area-volume/volume/volume-examples/sphere-volume-example

www.calculateme.com/cVolume/VolumeOfSphere.htm

This calculator will calculate the **volume of a sphere** given its radius.

www.wikihow.com/Calculate-the-Volume-of-a-Sphere

How to Calculate the **Volume of a Sphere**. A sphere is a perfectly round
geometrical object that is three dimensional, with every point on its surface
equidistant ...

www.aaamath.com/exp79_x8.htm

An interactive math lesson to teach how to find the **volume of a sphere**.