**How to Calculate the Circumference and Area of a Circle ...**
https://www.universalclass.com/articles/math/pre-algebra/how-to-calculate-circumference-area-circle.htm

Thus, a circle is simply the set of all points equidistant (that is, all the same distance) from a center point (P in the example above). The distance r from the center of the circle to the circle itself is called the radius; twice the radius (2r) is called the diameter. The radius and diameter are illustrated below. The Circumference of a Circle

**DA:** 17 **PA:** 6 **MOZ Rank:** 19