Question

Pls tell me about Origin of π ?

Answer 1

The number π is a mathematical constant, the ratio of a circle's circumference to its diameter, commonly approximated as 3.14159. It has been represented by the Greek letter "π" since the mid-18th century, though it is also sometimes spelled out as "pi"

I hope this helps.

Answer 2

it has two value
first 22/7
second 3.14
its short name (pi)