**A Quick Review of Working with sine, cosine, tangent**

## Sine, Cosine and Tangent

Let’s start with a quick review of the three trigonometric functions we already understand. Remember that these functions work only in right triangles.

**Example:** In right triangle ABC, hypotenuse length AB=15 and angle A=35º. Find leg length BC to the nearest tenth.

Set up the problem: Draw a right triangle. Position yourself at the given angle as a point of reference. Label the triangle’s sides as to their location: opposite, hypotenuse, adjacent. Place the given information on the triangle. Pair up the sides’ labels with the given information. The piece with no pairing is ignored. Set up the function based upon the pairings and solve.

Example: In right triangle ABC, leg length BC=15 and leg length AC=20. Find angle A to the nearest degree.

Set up the problem: The set up is the same as in the previous example. The only difference is that in this problem you will be finding the angle.