Final answer:
The sentence 'Peter, take down the stage sets after tonight's performance' shows an example of the imperative mood.
Step-by-step explanation:
The sentence that shows an example of the imperative mood is: Peter, take down the stage sets after tonight's performance.
The imperative mood is used to give commands or make requests. In this sentence, the speaker is giving a command to Peter to take down the stage sets. The verb 'take' is in the base form without any subject pronoun.
Learn more about Imperative mood in English grammar