The formula is simply this. Using a Formula Given the Circumference 1. To measure the circumference of a circle you need to use Pi a mathematical constant discovered by the Greek mathematician Archimedes.
C pd C pd where C circumference p 314 and d diameter.
Set up the formula for the circumference of a circle as a function of its area. 2 x p x radius where p is a mathematical constant equal to about 314159. In the above formulas p314159 and R is the radius. A line that is drawn straight through the midpoint of a circle and that has its end points on the circle border is called the diameter d Half of the diameter or the distance from the midpoint to the circle border is called the radius of the circle r.