Subtended

From Wikipedia, the free encyclopedia

In mathematics, "subtended" usually refers to the direct relationship between an angle and its arc length, or for solid angle the area on a unit sphere cut out by the envelope of the vectors defining the perimeter. For example, according to circle geometry, in a circle, equal angles subtend equal arc lengths. The converse is also true, equal arc lengths subtend equal angles. The solid angle subtended by a circular cone of opening angle (i.e. apex angle) $θ$ is $2 \pi \left (1 - \cos {\theta \over 2} \right)$ .

[edit] See also

Central angle

[edit] External links

How an angle is subtended by an object, Math Open Reference, With interactive applet
Angle definition pages, Math Open Reference, with interactive applets that are also useful in a classroom setting.