In geometry, the circle is a fundamental shape that holds immense importance. Central to a circle’s properties is its radius – the distance from its center to any point on the circumference. Knowing ...

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 circumference of a circle is the distance around the shape. The ability to round a number to a number of decimal places or to a number of significant figures means that answers can be written to ...