# Sine Function

Given the angle of a right triangle as input returns the ratio of the triangle's opposite side over its hypotenuse.

Sine takes in the angle of a right triangle as input and returns the ratio of the triangle’s opposite side over its hypotenuse. The angle is represented by the symbol theta (θ). Below is the graph for the function sin(θ), from 0 to 2π. For each angle the corresponding right triangle of hypotenuse one is displayed on the left. Drag either of the points to interact with the visual.

See the related function cosine and the more general concept: the unit circle.