The moving sofa problem asks for the planar shape of maximal area that can
move around a right-angled corner in a hallway of unit width. In 1992, Gerver
proved that the motion of a largest area moving sofa shape around the corner
can be parametrized such that its angle of rotation increases monotonically
and continuously. Furthermore, he conjectured that the total angle of rotation
should be π/2. The talk will consist of a short and mostly elementary proof of
this conjecture.