What is the Perimeter of a circle? The perimeter of a circle, also known as the circumference, is the distance around the edge of the circle. It is the length of the circle’s outer edge. The formula to calculate the circumference of a circle is C = 2Ï€r where C is the circumference and r is the radius of the circle.
For example, if the radius of a circle is 5 units, the circumference would be 2Ï€(5) = 2 * 3.14 * 5 = 31.4 units.
It’s worth noting that the diameter of a circle is just 2 times the radius, so one could also use the formula C = Ï€d instead of C = 2Ï€r where d is the diameter of the circle.
