a polygon, usually made from paper, that can be folded in certain ways to produce a series of faces
a polygon which folds or 'flexes'
a strip of paper folded up, which you can "flex" to reveal hidden faces
Paper folded along regular angles in such a way that faces are hidden and can be revealed by turning the paper "inside out"
In geometry, flexagons are flat models made from folded strips of paper that can be folded, or flexed, to reveal a number of hidden faces. They are amusing toys but have also caught the interest of mathematicians.