A dissection involves cutting a polygon into pieces in such a way that those pieces form another polygon; for a hinged dissection, the pieces must be attached by hinges. A piano hinge is "a long narrow hinge with a pin running the entire length of its joint." So, unlike regular hinged dissections, which swing or twist (around single point of hinge), pianohinged dissections fold along an edge. The book discusses the history, methods, and variations of these dissections. It has two special features: dissections entitled "Manuscript" display related material from the almost- lost manuscript by Ernest Irving Freese, and others entitled "Folderol" explore related subjects that are not piano-hinged dissections.
