This document discusses trigonometric ratios and solving trigonometric equations. It provides the definitions of sine, cosine, and tangent ratios relating the opposite, adjacent, and hypotenuse sides of a right triangle. An example problem is worked through to solve for the unknown side of a triangle using the sine ratio, substituting known values and rearranging the equation by multiplying both sides by the variable. A second example is presented using the tangent ratio to solve another trigonometric equation for the unknown side.