The moving sofa math problem: still unsolved 50 years later

[kingannoy]

@bheerssen

For a real challenge, move a sofa up a flight of stairs in a hallway with a 90 degree corner.

Did that once with a stair roughly like this but then with another 90° angel at the bottom.

Just stand it on it’s end and push it straight up, nothing difficult just really heavy and awkward.