The Moving Sofa Problem

What is the largest shape that can navigate an L-shaped corridor?

Sofa Shape

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About

Current: Semicircle
Area: π/2 ≈ 1.5708
1966 — Leo Moser poses the problem
1968 — Hammersley: π/2 + 2/π
1992 — Gerver: optimal shape ≈ 2.2195
2024 — Jineon Baek proves optimality