distance of the finishing point from the starting point = sqrt(500^2 + 600^2 - 2 x 500 x 600cos 120) = sqrt(250000 + 360000 - 600000(-0.5)) = sqrt(610000 + 300000) = sqrt(910000) = 953.9 km
Let the angle made by the finishing point at the starting point with the second point be A. Then
sin A / 600 = sin 120 / 953.9
sin A = 600 sin 120 / 953.9 = 0.5447
A = arcsin (0.5447) = 33 degrees.
Thus the bearing of the starting point from the finishing point is 100 + 33 = 133 degrees.
