NextPrevious

Mathematics Throughout History

The Creation of Zero and Pi

What are the measurements of a circle using pi?

There are many measurements of a circle. The perimeter of a circle is called the circumference; to calculate, multiply pi (π) times the diameter, or c = (πd), or pi (π) times twice the radius, (c = 2πr). The area (a) of a circle is calculated by multiplying pi (π) times the radius squared, or a = πr2.



Close

This is a web preview of the "The Handy Math Answer Book" app. Many features only work on your mobile device. If you like what you see, we hope you will consider buying. Get the App