Answer:
If the door was at the right angle then that means it is not an optical illusion, but if the door is straight then that means the door is not at a right angle so it's an optical illusion.
Step-by-step explanation:
Maybe if the door was straight, but you saw it at a right angle then maybe you were laying down, you were sick, seeing things or you drank a lot of alcohol that day. If it was a right angle on that day then it was not an optical illusion.