What is an equation that relates the circumference of a circle as a function of its diameter?

1 Answer
Mar 22, 2018

c=pi*d,
Where:
c is the circumference of the circle, and
d is the diameter of the circle.

Explanation:

This is a static relationship, meaning that no matter how large or small the circle is, the circumference will always be pi times a large as the diameter.

For example:

Say you have a circle with a diameter of 6 inches:

The circumference will be pi times that, or 6pi inches.
(18.849555... inches)

If you're given the radius, all you have to do is double the radius to get the corresponding diameter. Or, you can go straight from radius to circumference with the equation

c=2pir,
Where:
c is the circumference of the circle, and
r is the radius of the circle.

Hopefully this helped!