The formula for the circumference of a circle, c=πd or c=2πr, can also be used to find the diameter or radius of a circle.
Let's look at an example.
A circle has a circumference of 20.72 m. What is its diameter?
First, write down the formula.
c=πd
Next, fill in the values that you know.
20.72 m=3.14 d
Then, divide both sides of the equation by 3.14
6.6=d
The answer is the diameter is 6.6 meters.