A sailboat race course consists of four legs, defined by the displacement vectors A, B, C, and D. as the drawing indicates. The magnitudes of the first three vectors are A = 3.60 km, B = 4.70 km, and C=4.60 km. The finish line of the course coincides with the starting line. Using the data in the drawing, find (a) the distance of the fourth leg and (b) the angle . 23.0 2 B T 35.0 A 40.0 Finish. Start (a) Number i Units (b) Number i Units