In this excerpt from act i, scene i, of shakespeare's richard iii, what two purposes does richard's soliloquy appear to serve?

I would say that this excerpt (which is, by the way, one of the most famous and commonly quoted lines written by Shakespeare) serves to depict the motivations and personality of the character.

Richard describes himself in the excerpt, and states briefly why he decided to do what he did.

It develops the major characters of the play.

It informs the audience about the background of the plot.

Explanation:

where is the sentence at?

go to the home screen and it says what do you need to know? then type the