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]
(..) when they firebombed . There's gotta be a better way. but leave the train tunnel alone. Civilians can escape into the square, where our armies will be waiting for their surrender. We should have every available medic standing by. And if they won't surrender? (..)2015 The Hunger Games: Mockingjay - Part 2