Patent US 6,637,745

A system of pyramid puzzles provides sets of puzzle-pieces formed as identical spheres tangentially attached together in one or more row(s) on a square grid pattern, configured to provide interesting challenges with surprising solutions in assembling pyramids The puzzle system includes two families of sets of matched pairs of puzzle pieces for assembling pyramids of two corresponding equilateral shapes: triangle-based and square-based. For the triangular-based pyramid, puzzle-pieces are configured from single or plural attached rows of spheres forming rectangular outlines that each form an inclined layer in the pyramid. For the square-based pyramid, puzzle-pieces are configured in generally L-shaped orthogonal forms in matched pairs that each combine to form a horizontal layer in the pyramid. The sets can range from relatively simple with as few as four puzzle-pieces to larger sets of any desired size, increasing in progressive steps, in accordance with the teachings of the invention.