Question

Why might a speaker use a rhetorical question in a speech?

Answer 1

Think of it in everyday conversations. Usually we use rhetorical questions to help solidify a talking point, such as asking your friend whether or not they ate your sandwich even though you both know they did, winning the argument without having to argue. Basically  a speaker would use it to connect more with the audience by using a line of questioning in which the answers are already known by the audience, making their talking points more accepted.

Answer 2

A speaker might use a rhetorical question to give the speech or essay more depth and to make it so that the people become intrigued.