The word ‘flexagon’ is a portmanteau word, made by combining ‘flexible’ and ‘gon’ (‘gon’ meaning a flat geometric figure, as in ‘pentabgon’ or ‘hexagon’). Hence, flexagons are two- or three-dimensional configurations of cut and folded paper that can be flexed. Typically, a flexagon will have a surface which, after flexing, will be hidden inside the layers of the paper to reveal a new surface that in turn can be flexed out of view, to be replaced by the original surface or by a new one … and so on. Alternatively, instead of flexing faces in and out of view, a flexagon can also realign different sections of a single face in relation to each other, thus scrambling and reassembling an image.
If that sounds a little ...