Difference between revisions of "Radian"
| Line 1: | Line 1: | ||
A '''radian''' is a unit of measurement for [[angle|angles]]. In a circle, the measure of a [[central angle]] in radians is the ratio of the length of the [[intercepted arc]] to the length of the circle's [[radius]]. | A '''radian''' is a unit of measurement for [[angle|angles]]. In a circle, the measure of a [[central angle]] in radians is the ratio of the length of the [[intercepted arc]] to the length of the circle's [[radius]]. | ||
| − | A complete angle has measure <math>2\pi</math>, since a complete angle "intercepts" the whole circumference of the circle. Thus, radians can be converted to [[degrees]]: <math>2\pi\; rad=360^\circ</math> or <math>\pi \;rad=180^\circ</math>. | + | A complete angle has measure <math>2\pi</math>, since a complete angle "intercepts" the whole circumference of the circle. Thus, radians can be converted to [[Degree (geometry)|degrees]]: <math>2\pi\; rad=360^\circ</math> or <math>\pi \;rad=180^\circ</math>. |
[[Category:Geometry]] | [[Category:Geometry]] | ||
Revision as of 06:58, 17 March 2008
A radian is a unit of measurement for angles. In a circle, the measure of a central angle in radians is the ratio of the length of the intercepted arc to the length of the circle's radius.
A complete angle has measure 
, since a complete angle "intercepts" the whole circumference of the circle. Thus, radians can be converted to degrees: 
or 
.
