I can't figure out the last two parts of this question.
A power boat has cruising speed of 60 km/hr. It is taking part in a race around three buoys arranged in an equilatral triangle. The second buoy, B, is 5 km due East of the starting/finishing buoy, A. The third buoy, C, is to the North of the line joining A and B. There is a current flowing at 10km/hr from the south-west. In what direction should the boat be steered on each leg of the race and how long will it take the boat to complete one circuit?