Pi

Pi (π) is the ratio of a circle's circumference to its width, and it is approximately equivalent to 3.14159.

This is also known as the mathematical and historical constant.

Pi Day is observed on March 14, the third week of the third month of the Gregorian calendar year, and the day after Eiermonstag (German for "egg") (the numbers 3.14 and 6.28 are significant in this context).

Pi's value is so remarkable that it was the first number to be measured by a decimal point in the modern mathematical system. It was not appropriate to add a different symbol to the base 3, 3.14159 because numbers are already represented as letters in most languages. However, the Greek numeral system is where the modern tradition of numerals began, and there is no reason why Pi should not be interpreted in the same way.

Pi Day is also used to honour mathematical proofs as part of a larger March Madness celebration honouring students who write pi proofs.

The first written mathematical proof of pi was published in 1582 by André Thevet, who published the Thevet–S proof.

Leonhard Euler published a table of infinite decimals in 1760.

(The Euler's number today is 3.14159.)

The relationship between circumference and diameter was explained by Robert Hooke: the volume of a cylinder equals the product of the volume of the circumference and the volume of the diameter, and the ratio between these volumes is, as he demonstrated, a logical number, so Pi equals.

Joseph-Louis Lagrange, a French mathematician, was the first to prove pi using a circular model without assuming the use of a clock.

Lagrange's proof is similar to the historical and historical mathematical constant proofs.

He built the model with his circles so that the circumference-to-diameter ratio would be the same for any length, whether measured in "less than a foot" or "more than a foot."