1. Identifying parts of a triangle can help you find trigonometric ratios by seeing what side and angle measurements you have and if you have enough information to solve the triangle.
2. To use inverse trigonometric functions you should have to find the unknown measure of an angle of a right triangle when two side lengths are known. So, you simply use the same math as you would in trig ratios, but in a calculator you would have to click cos^-1, tan^-1, or sin^-1.
