In 1989, I began constructing domes using notched bars assembled according to a simple rule. This led me to explore planar constructions based on this rule using fixed length "notched" line segments. I was able to create a wide variety of patterns. Based on certain of these patterns I was able to construct spheres and cylinders from notched curved rods without the use of glue, rope, nails, or screws. Surprisingly, drawings found in the notebooks of Leonardo da Vinci suggest that he too explored constructions based on this simple rule.