# Calculating Pi

The circumference of a circle is the distance around a circle. The diameter is the distance across the circle that passes through its center.

For any circle, regardless of diameter, there is a consistent ratio between the circle’s circumference and the length of its diameter.

Watch this video to observe a mathematician’s exploration of this ratio, which he calls "pi."

For an extended version with a more detailed discussion about diameter and pie watch the video below. The video is filmed in the United Kingdom, so you will hear him referring to "football" which in the United States of America we call soccer.