Pi Day

Today is Pi Day:
Today is Pi Day, celebrated each year on March 14.

Pi, approximately 3.14159, is the mathematical constant representing the ratio between the diameter of a circle and the circumference represents.

Google is marking the holiday today with a Google doodle that some of the many formulas that depend on pi.

Here is a look at someone reading the first 100 digits of pi, which has an infinite number of digits.