A supplement to Ian's answer: Here is the largest-area sofa known, due to Gerver:
![GerverSofa][1]
Gerver, Joseph L. (1992). "On Moving a Sofa Around a Corner". Geometriae Dedicata 42 (3): 267–283. (Springer link.)
A supplement to Ian's answer: Here is the largest-area sofa known, due to Gerver:
Gerver, Joseph L. (1992). "On Moving a Sofa Around a Corner". Geometriae Dedicata 42 (3): 267–283. (Springer link.)