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Pi (
uppercase Π, lowercase π) is the fifth letter of the Greek Alphabet. It represents "p". In the Greek Numerals system, it has a value of 80.

Its Unicodes are:

U+03C0 π greek small letter pi (HTML: π π)

U+03A0 Π greek capital letter pi (HTML: Π Π)


Other Greek letters used in mathematics include:

  • Σ/Sigma : Either used as a Modulo Two-Sum or a N-ary Summation
  • ε/Epislon : A Euler (Pronounced "Oiler") constant
  • φ/Phi : Commonly used to stand for the golden ratio

And many others.