π+-+By+Julia+Roberts


 * π - By Julia Robertsπ ** (sometimes written **pi**) is an irrational [|mathematical constant] whose value is the [|ratio] of any [|circle] 's circumference to its diameter in the [|Euclidean plane] . It is approximately equal to 3.14159265.

The Greek letter π, often spelled out pi in text, was first adopted for the number as an abbreviation of the Greek word for perimeter "περίμετρος" (or as an abbreviation for "perimeter/diameter") by William Jones in 1706, but there is evidence of its concept first being used in 2000 BCE by the Babylonians.





http://oldweb.cecm.sfu.ca/pi/pi.html