pi is an irrational number. Since it is a non-repeating, non-terminating decimal, it cannot be written as a fraction.

The symbol for pi is "π". π = 3.141 592 653 589 793 238 462 643 383 279 ...

For calculations, pi (π) is usually approximated by using a limited number of digits after the decimal point. To two decimal places, pi is approximately 3.14.

One definition of pi is the ratio of the circumference of a circle to the length of the diameter of the circle.

There are many ways to define pi. Another definition is shown below: