Pi (letter)

Pi (uppercase/lowercase Π π), is the letter of the Greek alphabet, used to represent the "p" sound in Ancient and Modern Greek. In the system of Greek numerals, it had a value of 80. Letters that came from it include the Roman P and Cyrillic П.

In mathematics, the uppercase pi is used for the Pi product operator (for example. ), similar to the way summation is used. The lowercase pi is used as the mathematical constant pi, also known as Archimedes's constant.

 Related pages 
 Phi
 Tau

 References 

Category:Greek alphabet