Final answer:
The wave period can be calculated by dividing the total time it took for a certain number of waves to pass by a point by the number of waves.
Step-by-step explanation:
The wave period represents the time it takes for one complete wave cycle to pass by a given point. In this case, if it took 200 seconds for 20 waves to pass by you, you can calculate the wave period by dividing the total time by the number of waves. So, the wave period would be 10 seconds (200 seconds ÷ 20 waves).