Can a rectangle be a square? In certain cases it seems to meet the definition.

;D ;D Oh, Oh! I know! I know! *calls on me* ;D :D Ok, listen carefully! A square can be a rectangle, but a rectangle CANNOT be a square! Understand? *bobs head up and down* ;DGood! ;D

Only a square can be a rectangle, not the other way around. You're not alone, my friends always forget that. A square has all four sides that are equal.