An interior designer has a dilemma. She has to move an amazingly heavy armchair which is up against a wall. The chair needs to be sitting so it is exactly beside its starting position and facing the same way.
If the only possible movement is to rotate the chair on any of its corners, how can the chair be moved to its new position?
(In reply to
re: Imperfect Armchair Solution - I'm wrong by nikki)
I think your generalization still works if the chair has a space of distance D between the wall and the chair.