Monday is March 14 — in other words, it's Pi Day!
The first six digits in pi are 3.14159, so math enthusiasts deemed March 14 as Pi Day, which later became a day to celebrate the sweet dessert along with pizza.
Pi is the ratio of the circumference of a circle to its diameter. It's not equal to the ratio of any two whole numbers, so an approximation -- 22/7 -- is used in many calculations.
Pi is essential in architecture and construction and was used frequently by early astronomers. Pi has been known for about 4,000 years, but it started to be called by the Greek letter only in the 1700s.
The origin of Pi Day
Pi Day started 34 years ago at San Francisco's Exploratorium.
Physicist Larry Shaw, who worked in the electronics group at the museum, started celebrating pi on March 14, 1988, primarily with museum staffers.
The tradition has grown to embrace math enthusiasts from all walks of life.
Click here to learn more about Pi Day.
