C pd C pd. To calculate the diameter of a circle multiply the radius by 2. A circle has a diameter of 10 m.
The next equations show how you can instead find the diameter from them.
Where C circumference p 314 and d diameter. C 10 x 314 C 314 m. Divide the diameter by 2 to find the radius. If written instead in terms of the radius the diameter is very simple.