Difference between revisions of "Circumference"
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− | '''Circumference''' | + | '''Circumference''' is essentially a synonym for [[perimeter]]: for a given [[closed curve]] in the [[plane]], it is the distance one travels in a complete circuit of the curve. The term circumference is most frequently used to refer to the distance around a [[circle]], though it may refer to the distance around any [[smooth]] curve, while the term perimeter is typically reserved for [[polygon]]s. |
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+ | In a circle of [[radius]] <math>r</math> and [[diameter]] <math>d = 2r</math>, the circumference <math>C</math> is given by <math>C = \pi \cdot d = 2\pi \cdot r</math>. Indeed, the [[constant]] <math>\pi</math> ([[pi]]) was originally defined to be the [[ratio]] of the circumference of a circle to the length of its diameter. | ||
==See also== | ==See also== | ||
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Revision as of 09:32, 13 July 2007
This article is a stub. Help us out by expanding it.
Circumference is essentially a synonym for perimeter: for a given closed curve in the plane, it is the distance one travels in a complete circuit of the curve. The term circumference is most frequently used to refer to the distance around a circle, though it may refer to the distance around any smooth curve, while the term perimeter is typically reserved for polygons.
In a circle of radius and diameter , the circumference is given by . Indeed, the constant (pi) was originally defined to be the ratio of the circumference of a circle to the length of its diameter.