Refers to the Greek letter π itself, used in various contexts such as mathematics, science, and fraternity names.
ギリシャ文字のπは「パイ」と読む。
The Greek letter π is read as 'pi'.
Only when written π
The mathematical constant approximately equal to 3.14159, representing the ratio of a circle's circumference to its diameter.
円周率πは約3.14です。
The circular constant pi is approximately 3.14.
Only when written Π
Uppercase Π used in mathematics to denote the product of a sequence, analogous to Σ for summation.
Πは数列の積を表す記号です。
Π is a symbol representing the product of a sequence.
Standard mathematical symbol for the constant pi; also used for the Greek letter in general contexts.
Katakana spelling commonly used when the Greek letter is not available or in casual writing.
Uppercase form used specifically for product notation in mathematics.
Borrowed from English 'pi', ultimately from Ancient Greek πεῖ (peî).