Shahad Al-Mullah, Pi (\pi) is a Mathematical constant and is the ratio; the circumference to the diameter of a circle. Its approximate value is Pi(\pi)= 3.14159.

The constant Pi is also called Archimedes' constant.

This is a very basic idea/ concept of Pi.

Thanks!

- Muhammad Sinan

Hi, Muhammad gave the natural answer. In addition capital Pi is used to denote tha product of elements.

It can be viewed as the length of circumference of a circle of half radius.You shall measure it using a thread. It can be also viewed as in square unit the area of unit circle( radius=1unit).In number line it can be represented at a distance 22/7 unit from zero. In calculator you shall see the symbol. In radian measure it is equal to 180 degree. For calculation of angles radian or degree measure is used. Pai cannot be represented as a simple fraction. So it is a famous irrational number. In philosophy of Mathematics, pai can be seen as related with something which cannot be restricted. Some romantic poets (example- John Keats ) sometimes explain eternity of art .Its because they fail to explain all its beauty due to their limited skill of writing. I am not a romantic poet, but I see Pai has quality just like eternity of art.