Measure of the curved line that forms a circle.
Formula
The formula for the circumference C of a circle with radius r is: C = 2πr.
The formula for the circumference C of a circle of diameter d is: C = πd.
The formula for the circumference C of a circle with radius r is: C = 2πr.
The formula for the circumference C of a circle of diameter d is: C = πd.