Pi (letter)

Greek alphabet
Α α Alpha	Β β Beta
Γ γ Gamma	Δ δ Delta
Ε ε Epsilon	Ζ ζ Zeta
Η η Eta	Θ θ Theta
Ι ι Iota	Κ κ Kappa
Λ λ Lambda	Μ μ Mu
Ν ν Nu	Ξ ξ Xi
Ο ο Omicron	Π π Pi
Ρ ρ Rho	Σ σ Sigma
Τ τ Tau	Υ υ Upsilon
Φ φ Phi	Χ χ Chi
Ψ ψ Psi	Ω ω Omega
obsolete letters
Ϝ ϝ Digamma	Ϻ ϻ San
Ϙ ϙ Qoppa	Ϡ ϡ Sampi

Pi (upper case Π, lower case π) is the 16th letter of the Greek alphabet. In the system of Greek numerals it has a value of 80.

In Greek, the letter is pronounced /piː/; in English, though, it is pronounced /paɪː/ (as the word pie). In words, it is pronounced /p/. In Modern Greek, the sequence of letters μπ represents the /b/ sound, as in boy (the second letter of the Greek alphabet is now pronounced /v/ as in very).

The upper-case letter Π is used as a symbol for:

The product operator in mathematics (similar to a series).
In textual criticism, Codex Petropolitanus, a 9th century, uncial codex of the Gospels, now located in St. Petersburg, Russia.

The lower-case letter π is used as a symbol for:

The mathematical constant π ≈ 3.14159, the ratio of a circle's circumference to its diameter.
The prime counting function in mathematics.
Dimensionless parameters constructed using the Buckingham Pi theorem of dimensional analysis.
The elementary particle called the pi meson or pion.
Profit in microeconomics.
Inflation rate in macroeconomics.

Categories: Greek letters