Gerver's Sofa (Approximation)
Corridor: - Top hallway: left to right (0 ≤ x ≤ 600), 0 ≤ y ≤ 100
- Side hallway: top to bottom at x≈600 (600 ≤ x ≤ 700), y≥0
Sofa travels along center line y=50 horizontally, then pivots down at x=650.

Red line = centroid path.
Faint curves = previously occupied sofa boundary.
Current sofa shape not drawn, only centroid shown.
Click "Play" to restart animation.