pi

Pronunciation

• enPR: pī
• IPA: /paɪ/
• SAMPA: /paI/
•  Audio (US)^{help, file}

Homophones

• pie

Noun

Singular pi

Plural pis

Lower case pi

Pi is equal to a circle's circumference divided by its diameter

1. Pi is a Greek letter written "π".
2. (mathematics) Pi is a number that is found by dividing the circumference of a circle by its diameter. Pi is constant, it is always the same (close to 3.14159). It is usually written as "π"

   The distance around a circle is twice the radius times pi; C = 2πr.