In the same math textbook, Allen talks about the formula for right circular cylinder , which is used to measure volume (145). And you use that formula to measure the volume of the hockey puck.

Circles, sectors and arcs - Edexcel The circumference of a circle is its outside edge, and is the same distance from the centre at every point along its length. This distance is called the radius.

As we celebrate again in 2018, here are some Pi Day facts you should know. What Is Pi? Pi represents the ratio of a circle’s circumference to its diameter.