Sine of Supplementary Angle

Theorem

 * $\map \sin {\pi - \theta} = \sin \theta$

where $\sin$ denotes sine.

That is, the sine of an angle equals its supplement.

Also see

 * Cosine of Supplementary Angle
 * Tangent of Supplementary Angle
 * Cotangent of Supplementary Angle
 * Secant of Supplementary Angle
 * Cosecant of Supplementary Angle