No one, it is a physical property of a circle.
At the same time as the circle
It was not invented but discovered by ancient mathematicians who found that the circumference of any circle when divided by its diameter is always the same ratio for any circle.
Pi is the relationship between the diameter and the circumference of a circle.
The circumference of a circle is the perimeter of the circle for a given diamater.
The perimeter of a circle is its circumference
Nobody is the circumference of a circle!
The round perimeter of circle is its circumference
The perimeter of a circle is its circumference
The distance around a circle is its circumference
The formula; 2 * Pi * Radius = circumference Will calculate the circumference of a circle.
The circumference of a 9 circle is: 28.3
The circumference of a 30 circle is: 94.25