The mathematical constant that is the circumference of a circle divided by its radius, equal to twice pi.

Some have suggested that pi is the wrong choice of constant to describe the geometry of circles etc. and tau = 2*pi would have been better. Most practising mathematicians think this is silly. The xkcd comic strip facetiously proposed a compromise of 1.5*pi or "pau".

The Pi Manifesto.

Last updated: 2013-12-10

Nearby terms:

tastetatartautautological probabilitytautological settautology

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