Answer
The best sailing angle is $105{}^\circ $ and the speed at that angle is 7.5 knots.
Work Step by Step
The speed is represented by the first component of the point and the sailing direction is represented by the second component .
A sailboat racer would like to choose a direction angle that gives him the maximum speed.
Of the four points, 7.5 is the highest speed component and the corresponding direction angle is $105{}^\circ $.
