March 14 (3.14) is Pi Day. As we all know, Pi (symbol: ) is a mathematical constant which is the ratio of the circumference of any circle to its diameter. That means that if we measure the circumference of a circle and divide it with its diameter, then the quotient is always . The constant is an irrational number; it starts with 3.14 and continues forever.
Pi Day was created 1988 by Larry Shaw, a physicist at the San Francisco Exploratorium.