Sam's "bearing" is simply the direction in which he's moving, which is the angle made with due East.
From point A to point B, his bearing is 335°, and from point B to C, his bearing is 45°. In both cases, the angle is made with due East from the second point. See the sketch for a rough approximation of this. Note that it is not to scale.
To get it into scale, you have to compute the distances traveled along each bearing.
• Moving at 6 km/h for 20 min = 1/3 h would cover a distance of
(6 km/h) • (1/3 h) = 2 km
• Moving at 10 km/h for 15 min = 1/4 h would mean a distance of
(10 km/h) • (1/4 h) = 2.5 km
In your sketch, 1 cm should represent 500 m = 0.5 km, so the arrow from A to B should have a length of 4 cm, while the arrow from B to C should have a length of 5 cm.