Today 14th March, sometimes written 3.14, is pi day (π). The number π is a mathematical constant, and is calculated from the ratio of a circle’s circumference to it’s diameter.
π is an irrational number. Any number that cannot be expressed as a ratio of two integers is described as irrational. Their decimal representation neither terminates nor infinitely repeats but extends infinitely without repetition and π is such an example.
For your interest and pleasure here is π to one hundred decimal places:
3.1415926535 8979323846 2643383279 5028841971 6939937510 5820974944 5923078164 0628620899 8628034825 3421170679 …