Posted by Pam on Friday, December 19, 2008 at 12:28pm.
Two fire towers, A and B, are 20.3 km apart. From tower A, the bearing of tower B is 70̊. The ranger in each tower observes a fire and radios the bearing of the fire from the tower. The bearing from tower A is 25̊ and from tower B is 345̊. How far is the fire from each tower?

Math  Damon, Friday, December 19, 2008 at 1:13pm
triangle A B F
North to AB = 70
North to AF = 25
so
angle FAB = 7025 = 45
North to BF = 345 clockwise so 15 counterclockwise
so exterior angle AB to BF = 70 +15 = 85
so
angle ABF = 180 85 = 95
that leaves angle AFB = 180 4595 = 40
then
sin 40/20.5 = sin 95/af = sin 45/bf 
Math  Pam, Friday, December 19, 2008 at 2:27pm
ohh thanks