The π number (3,14) is a mathematical constant that is the ratio of a circle’s circumference to its diameter.
It has been represented by the “Π” from the Greek word «περιφερεια» for circumference. π can not be expressed exactly as a ratio of two integers consequently, it s decimal representation never ends and never repeats.
Moreover, π is a transcendental number that implies that it is impossible to solve the ancient challenge of squaring the circle. The first 50 decimal digits of π are :
3,14159 26535 89793 23846 26433 83279 50288 41971 69399 37510
The decimal representation of π reaches over 10 trillion digits. Scientific applications generally require no more than 40 digits of π.
For example with 11 decimal digits of π can be computed a circle that fits in Earth and the error will be less than 1mm.
With 39 decimal digits can be computed a circle that fits to the entire visible universe and the error will be as is the radius of the hydrogen atom.