Right triangle trigonometry involves the relationship between angles and side ratios in right triangles. Given a right triangle, we can find the sine, cosine, and tangent of the non-90º angles. From there, we can also find cosecant, secant, and cotangent.

The hypotenuse is the side across from the right angle, the opposite side refers to the side across from the angle x, and the adjacent side refers to the side next to, or touching the angle x.