So my question was related to the following problem - A person is sailing their boat, and their GPS says they are 10km from town A, and 8km from town B. The angle between the towns in 80 degrees. I found how far apart the towns are - about 11.7km using the law of cosines. However, the last part asks the angle of elevation of the heli as seen from the boat.
The helicopter is 1000m high, and is in between the 2 towns, so 5.85km from each town. How do I get the angle of elevation? I don't know how to start.