A square is drawn on a sheet of paper. Of course, all its angles are equal to each other.
Can you pull out one of the corners, while expanding the other two?
No, no, this does not have to stretch the paper. You need to change angles only visually.
Have you already tried? Let's see how it could be done!
You see - with the help of broken lines we visually reduced one corner, and two - increased.
This problem can also be represented in the reverse order.
Show your friends a square, drawn by broken lines (only not on a sheet in a cage). And ask them to choose the largest and smallest corners.
Or just ask if the angles are equal or not.