Sine Function

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

Right Triangle with labeled sides

The angle of the right triangle is represented by the symbol theta (θ). Below is the graph of the functions input and output of function sin(x), 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.

Good Links

Right Triangle | concept
Radians | concept
Unit Circle | concept
Law of Sines | concept
Sine | graph
Trigonometric Functions | concept
Cosine | function