1. Objective: Apply the law of cosine. (SAS) and (SSS)
Warm up
Find the area of the triangle: b = 10, c = 24,

2. Law of Cosines Case 3: two sides and the included angle are known (SAS). Case 4: three sides are known (SSS). Example 1 Solve the triangle.

3. Example 2 Solve the triangle.

4. Example 3. Two airplanes leave an airport at the same time on different runways. One flies directly north at 400 miles per hour. The other airplane flies on a bearing of N75°E at 350 miles per hour. How far apart will the airplanes be after two hours?