Make sure the post is 'square' to the floor. [=make sure that there is a right angle where the post and the floor meet]
I'll go on the trip if I can 'square it with' my parents. [=if my parents will agree to let me go]
Here's the rest of the money. Now we're 'square'. [=now we don't owe each other anything]
(..) Mod f x square dx. So please finish Percival by next time. I know many of you had this as undergraduates, but it won't hurt to brush up. Thank you, Steven. (..)1997 Good Will Hunting