Have you ever looked up a word in the dictionary and found that definition filled with other words you didn't know? When I say "looked up a word in dictionary" I meant the Internet, of course. Also, there are those things called two-column proofs. Maybe, like the boogeyman, your parents or siblings have used these to scare you into behaving. We'll be introducing those as well.

Geometry 4(A) Distinguish between undefined terms, definitions, postulates, conjectures, and theorem