Sine is Reciprocal of Cosecant

Theorem
Let $\theta$ be an angle such that $\sin \theta \ne 0$.

Then:
 * $\sin \theta = \dfrac 1 {\csc \theta}$

where $\sin$ denotes the sine function and $\csc$ denotes the cosecant function.

Also see

 * Trigonometric Functions in terms of each other