March 14 Marks National Pi Day

LOS ANGELES (CBS) — Today is National Pi (∏) Day.

Pi or 3.14159265 etc. is the relationship between the circumference (perimeter of a circle) and the diameter (distance across a circle). It is an irrational number that will continue infinitely without repeating.

22/7 or 3.14 is used for short of Pi but is not completely accurate. With the help of computers, it has been estimated to be over 1 trillion digits past its decimal point.

Pi Day began in 1989 at the San Francisco Exploratorium . Visitors were asked to participate in Pi-related activities and were invited back to eat apple pie.

Mathematicians used to be the only ones that reflected upon this day. However, in 2009, the U.S. House of Representatives passed and recognized March 14 as National Pi Day.

March 14 also happens to be Albert Einstein's birthday.

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