Final answer:
When entering or turning at an intersection, always look left and right to ensure safety. Furthermore, from the perspective of a bicyclist moving to the right, a stationary person on the sidewalk appears to be moving to the left due to the relative motion.
Step-by-step explanation:
When you are turning, driving through, or entering an intersection you should always look left and right. It is important to check both directions to ensure that the way is clear and it is safe to proceed. This is a fundamental rule of safe driving practices that helps prevent accidents. Not only should you look left and right, but you also need to be aware of the traffic straight ahead and any potential hazards that might affect your path of travel.
In the reference frame of a bicyclist passing by toward your right while you stand on a sidewalk, you would be moving to the left. This is because in the reference frame of the bicyclist, everything around them, including someone standing still, appears to move in the opposite direction of their travel. Hence, as the cyclist moves to the right, from their perspective, the stationary observer on the sidewalk is moving to the left.