Circumference
From Wikipedia, the free encyclopedia.

The circumference is the distance around a closed curve. The circumference of a circle can be calculated using the formulae:

• circumference = 2 π r
• circumference = π d

where r is the radius and d is the diameter of the circle, and π (the Greek letter pi) is the constant 3.14159...

The original article can be found at: http://en.wikipedia.org/wiki/Circumference.
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