The circumference is the perimeter of a circle. It is a length and so is measured in \(mm\), \(cm\), \(m\) or \(km\). An area is measured in square units: \(mm^{2 ...

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 ...