Trigonometry ratios are: Sine, cosine, and tangent. Sine is defined by the ratio of the opposite side to the reference angle to the hypotenuse; cosine is defined as the ratio of the side adjacent to the reference angle to the hypotenuse; and the tangent is the ratio of the opposite side to the reference angle to the adjacent side to this same angle. You have that each ratio has an angle corresponding to it, and vice versa.
In this applet you may drag any of the two vertices of the acute angles to see in a dynamic way this correspondence.
Didn't you find what you were looking for? Do your search here!