Question 1157456
F for FIRE, and stations A and B, triangle


Triangle ABF, 
Angle at A is 72 degrees.
Angle at B is 58 degrees.
Angle at F is  180-72-58 degrees or 50 degrees.



If you feel it is necessary, law of sines gives
{{{sin(72)/BF=sin(50)/2=sin(58)/AF}}}.