A radar station located at point A is tracking ships at points B and C. How far apart are the two ships, to the nearest tenth of a kilometre?
Using the Law of Cosines
BC^2 = 4.9^2 + 6.8^2 - 2 ( 4.9 * 6.8)cos (70°)
BC^2 = 47.46
BC = sqrt ( 47.46) ≈ 6.9 km