Final answer:
The total length of a race course would be the perimeter if it's a closed loop. Without specific details of the race course, the exact measurement cannot be provided, but several examples hint at how the length can be determined if more information is available.
Step-by-step explanation:
The student's question pertains to the total length of a race course. To ascertain the total length, one would typically consider the perimeter of the race track if the course returns to the start line or the straight distance from start to finish if not returning. This question does not provide specific details about the dimensions or shape of the race course, which are necessary to give an exact measurement. However, if we refer to the provided information, option (a) says that the perimeter is the distance, and the shortest distance between the start and finish line is the magnitude of displacement. This suggests that the total length could be measured by the perimeter if it's a closed loop.
Some examples include a marathon which has a set length of 42.188 km, or a soccer field where the perimeter would be the sum of all sides, assuming the field was used for a running event. For an actual racecourse, you would need to know the specific dimensions or shape to calculate the total length.