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title: PI
---
## PI

`PI = 𝜋 = 3.14159265359...`

PI is a mathematical constant whose value is approximately equal to 3.14159265359.... It is defined as the `ratio of circumference of a circle to its diameter`. The PI is represented by a greek letter `𝜋` and is widely used in Physics and Mathematics. PI is infinitely long, meaning it has no end. PI is also irrational, meaning it does not have a pattern / repeat (at least that we have discovered).

The ratio 𝜋 = circumference/diameter always remains the same, regardless of the size of a circle. For example, even if we take a new circle of twice the diameter of a previous circle, then the circumference of that new circle will be exactly double of the previous one preserving the value of 𝜋 to be constant.

Note: Though Pi irrational, because its decimal repeats infinitely, the number itself is not infinite because it is contained between 3 and 4.