Circumference Calculator

A circle calculator that starts from the radius, the diameter or the circumference, whichever measurement you already have. Enter one of them and it returns the other two along with the area, using C = 2 x pi x r. Answers come back in the unit you typed, so feet in means feet out and square feet for the area. It suits laying out a circular bed, sizing a pipe or checking a geometry answer, and it assumes a true circle rather than an oval.