Originally Posted by

**shadow6** The following questions are for a final class project. Obviously these questions are very hard, and I am unsure how to completely answer these with the proper and complete work shown. Help on answering these questions with work/ steps would be greatly appreciated.

9. Two airplanes leave the airport at the same time. One travels 355 km/h and the other 450km/h. Two hours later they are 800km apart. Find the angle between their courses.

10. Two helicopters flying at an altitude of 250m are 2000m apart when the spot a life raft below. It is directly between them. The angle of depression (AoD) between one and the raft is 37°. The AoD between the other and the raft is 49°. Both are flying 170km/h. How long to the nearest second will it take the nearest aircraft to reach the raft?