GeoFit vs Spirolaterals

Based on Donna Bretl's wood "Bretl Blocks" puzzles, GeoFit challenges you to fit small squares, diamonds, triangles, and trapezoids into square, hexagonal, and octagonal frames. Lots of "solutions" are possible, resulting in a wide variety of interesting, surprising, and beautiful patterns.

Spirolaterals allows you to explore geometric line designs based on applying a simple rule to a number sequence. Be warned though: spirolaterals can be very addictive! You can create your own spirolaterals by entering a number or text like your name. Or you can explore the gallery of 80 spirolaterals by tapping Surprise Me! Spirolaterals raise many interesting questions: Which ones repeat and why? What kinds of symmetry are present? What happens when you use a palindrome or when your numbers increase or decrease by the same amount? I have used Spirolaterals in my math classes for many years, and students always find them fascinating. They try their name or phone number. They try to create some particular pattern. This year some students spent hours trying to create a 4x4 grid! If you create an interesting spirolateral, email me and I may include it in the Surprise Me! gallery in a future version, with full credit to you!