A puzzle in which each of a number of regular octagons is divided to form an irregular octagon and a number of smaller pieces. Each irregular octagon has four pairs of equilateral parallel sides. Each of the smaller pieces has two pairs or three pairs of equilateral parallel sides. The sides of all parts formed are equal in length. A number of the pieces are capable of being assembled in juxtaposition to form a large regular octagon, which assembly can be performed in a large number of different ways.