Pi Day is celebrated globally on March 14 every year to recognise the mathematical constant, Pi. The approximate value of Pi is 3.14. The date, when written in the format of month/day (3/14), matches the first three digits of the mathematical constant.

**History of Pi Day**

In 1988, Physicist Larry Shaw first recognised Pi Day.

In 2009, the United States House of Representatives designated March 14 as Pi Day. Later, UNESCO marked Pi Day as the ‘International Day of Mathematics' during its general conference in 2019.

Mathematician and physicist, Albert Einstein, known for the "General Theory Of Relativity" was born on Pi Day in 1879.

The value of Pi was first calculated by a mathematician named Archimedes of Syracuse. It was later accepted by the scientific community when Leonhard Euler used the symbol of Pi in 1737.

Later Physicist Shaw linked up the digits of Pi with March 14 to organise a special day for the staff of Exploratorium in San Francisco. March 14 is also celebrated as the ‘Super Pi day' when the first 10 digits of Pi were achieved at 9:26:53 am in 2015 forming the exact moment along with the date as (3/14/15/92653).

Pi Day is celebrated by lovers of mathematics every year through Pi recital competitions and Pi Day workouts to stimulate interest in learning and practising mathematics.

**Significance Of Pi **

Pi is an infinitely long, irrational number and its exact value cannot be known. Since Pi's exact value cannot be known, we can never find the exact area or circumference of a circle.

Pi is a part of Egyptian mythology. People in Egypt believed that the pyramids of Giza were built on the principles of pi.