The number π (/ paɪ / ⓘ; spelled out as pi) is a mathematical constant, approximately equal to 3.14159, that is the ratio of a circle 's circumference to its diameter.

Nov 17, 2025 · pi (π), in mathematics, the ratio of the circumference of a circle to its diameter. The Greek letter π was first used by British mathematician William Jones in 1706 to represent …

The greek small letter π (pi) is a geometric constant approximately equal to 3.1416. The numeric value is equal to the length of any circle's circumference divided by its diameter.

Draw a circle with a diameter (all the way across the circle) of 1. Then the circumference (all the way around the circle) is 3.14159265... a number known as Pi. Pi (pronounced like "pie") is …

Pi is an irrational number. An irrational number does not have a repeating pattern and does not end, so it can only be approximated. Calculated to one hundred places after the decimal: π ≈ …

2 days ago · π π is the ratio between a circle's circumference and diameter. That is, circumference diameter = π diametercircumference = π. π π is a fundamental constant in …

The constant pi, denoted pi, is a real number defined as the ratio of a circle's circumference C to its diameter d=2r, pi = C/d (1) = C/ (2r) (2) pi has decimal expansion given by …

2 days ago · Pi is a mathematical constant whose value is the ratio of any circle's circumference to its diameter in Euclidean space; this is the same value as the ratio of a circle's area to the …

The pi symbol (π) is a Greek letter used to represent the ratio of a circle’s circumference to its diameter. It’s been used in this way for over 250 years.

It is defined as the ratio of a circle's circumference to its diameter, and it also has various equivalent definitions. It appears in many formulas in all areas of mathematics and physics. It …