Can you play with square goal post?

Answer 1

there is no guidance on the FA website, however on FIFA.com website under laws of the game law1 it allows for square, rectangular, round and eliptical goalposts

Answer 2

yes. in a little village outside of Nice, France, the have a Boule tournament every year, and they use square balls instead of round ones.

Answer 3

Not unless you are the ace, or someone got out and you are giving it to ace for them to start a new round