The radius of a circle or a sphere is the distance between the center and the edge. The radius can be used to calculate a circle's diameter, area and circumference. Likewise, a sphere's volume is ...

The number represented by pi (π) is used in calculations whenever something round (or nearly so) is involved, such as for circles, spheres, cylinders, cones and ellipses. Its value is necessary to ...

The circumference of a circle is the distance around the circle. It is another name for the perimeter of a circle. The circumference of a circle is calculated using the formula: \(\text{circumference} ...