This document discusses using trigonometric ratios to solve right triangles. It begins with an example of using the cosine ratio to determine which angle of a right triangle is ∠A. Subsequent examples demonstrate using the sine and tangent ratios to identify angles, calculating angle measures from trigonometric ratios using inverse functions, solving right triangles given side lengths or an angle measure, and solving a right triangle given in the coordinate plane. Real-world applications of solving right triangles to find road grades are also presented.