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Pi

Concept

Pi

The number pi is a constant defined as the ratio between the circumference and the diameter of a circle. This ratio is the same in every circle. Pi is usually written with the Greek letter π.\pi. π=3.1415926\begin{gathered} \pi=3.1415926\ldots \end{gathered} Note that since π\pi is an irrational number, its value is often rounded to 3.143.14 to make calculations easier.