Moving Sofa and Other Math Problems No One Can Solve

So you’re moving into your new apartment, and you’re trying to bring your sofa. The problem is, the hallway turns and you have to fit your sofa around a corner. If it’s a small sofa, that might not be a problem, but a really big sofa is sure to get stuck. If you’re a mathematician, you ask yourself: What’s the largest sofa you could possibly fit around the corner? It doesn’t have to be a rectangular sofa either, it can be any shape. Read about this and other math problems that anyone can understand, but nobody has been able to solve.