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 ...

I’m a journalism student in college, and math is one of the requirements for not only graduation, but also to help me transfer to a four-year school. There are going to be some situations coming my ...

Imagine a piece of string wrapped around the Earth's equator - that's about 40,000km. How much MORE string would you need for it to sit 15cm above the ground, all the way around? The important thing ...

Introduction If you wanted to measure the circumference of Earth, how long would your tape measure have to be? Would you need to walk the whole way around the world to find the answer? Do you think ...