Which formula am I supposed to use to find the distance from each station to the fire?

Question

Two fire lookout stations are 10 miles apart, with station B directly east of station A. Both stations spot a fire. The bearing of the fire from station A is N25°E and the bearing of the fire from station B is N56°W.

Answer 1

Make a drawing; you will have a triangle and you will be able to figure out all of its internal angles, using the given bearings. Then you can use the Law of Sines.