#### 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 $.