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 formula for finding the area of a circle is 𝑨 = π𝒓² The ability to round a number to a number of decimal places or to a number of significant figures is essential if answers are to be written to ...

It is once again Pi Day (March 14—which is like the first digits of pi: 3 and 14). Before getting into this year's celebration of pi, let me just summarize some of the most important things about this ...