A surveyor wishes to calculate the distance between the two trees B and C across a river from where he is standing. If the distance from his position, A to B is 70 meters, the distance from C to A is 100 m,and the angle of A is 56°42',determine the distance between the two trees.

Answer 1

using the law of cosines, the distance d is found from

d^2 = 70^2 + 100^2 - 2*70*100 cos56°42'