Posted by Haley on .
two lighthouses A and B are positioned along the coast.A ship is positioned 30 miles from lighthouse A and 40 miles from lighthouse B.The angle between the line of sight from the ship to lighthouse A and the line of sight to lighthouse B is 33 degree. what is the distance between lighthouse A and lighthouse B

precalc 
Steve,
As usual, draw a diagram. This is where the law of cosines comes in. The distance x from A to B is
x^2 = 30^2 + 40^2  2(30)(40)cos33°
x = 22.07