This room was devised by the artist Adelbert Ames, Jr., to show just how deceptive the geometry of three-dimensional objects can be. We think that we see a rectangular room inhabited by two abnormal people; but the room is not rectangular, and its planes - walls, floor, and ceiling - are not set at right angles to each other. It is actually a six-sided irregular construction with sloped floor, ceiling, and rear wall, inhabited by people of normal size.