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 ...

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 ...

Forbes contributors publish independent expert analyses and insights. I write about mathematics and its applications The area and perimeter ratios are shown and as n ...

There’s too much news. We help you understand what you really need to know. Vox delivers the depth, context, and clarity you need to understand what’s happening and why it matters. We rely on readers ...