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

Pi (/ˈpaɪ/; Ancient Greek /piː/ or /peî/, uppercase Π, lowercase π, cursive ϖ; Greek: πι [pi]) is the sixteenth letter of the Greek alphabet, meaning...

π, or Π in Wiktionary, the free dictionary. Pi (π) is a mathematical constant equal to a circle's circumference divided by its diameter. Pi, π or Π may...

Approximations for the mathematical constant pi (π) in the history of mathematics reached an accuracy within 0.04% of the true value before the beginning...

In theoretical computer science, the π-calculus (or pi-calculus) is a process calculus. The π-calculus allows channel names to be communicated along the...

pi meson, denoted with the Greek letter pi ( π ), is any of three subatomic particles: π0 , π+ , and π− . Each pion consists of a quark and an antiquark...

In engineering, applied mathematics, and physics, the Buckingham π theorem is a key theorem in dimensional analysis. It is a formalisation of Rayleigh's...

The Π pad (pi pad) is a specific type of attenuator circuit in electronics whereby the topology of the circuit is formed in the shape of the Greek capital...

In chemistry, pi bonds (π bonds) are covalent chemical bonds, in each of which two lobes of an orbital on one atom overlap with two lobes of an orbital...

less than or equal to some real number x. It is denoted by π(x) (unrelated to the number π). Of great interest in number theory is the growth rate of...