In the left, the original Jansen’s mechanism with it’s walking curve, and in the right, a simplified version.
A la izquierda, el mecanismo original de Jansen y su “curva de caminata”, y a la derecha una versión simplificada.
Jennifer Silverman, partner in GGB crime, hooked me into this project. (Meaning she mentioned it on twitter and it was cool.) She made this sketch, which is super fun. I couldn’t really figure out her construction method, so I made one of my own. (Occurs to me now I was supposed to generalize it… oops. Later.)
These are from my version. I accidentally discovered the fun of putting the circles out of phase (like in the second picture). But then I wanted to tessellate them, so I went back to the simpler design and made a tool.
the method to make fractals out of the first 11 polygons. you’re welcome!
Several of my preservice elementary teachers got interested in triangle art and that sparked my interest.
This is made from all rotations of the original triangle, and colored to make as many patterns as possible.
Play yourself and see what you can make! On GeoGebraTube for download or mobile.
Trying to figure out how to make the coloring pattern consistent, and finding the rotations to fit in as rotations required some fun problem solving thinking.
Minimal Posters - Five Of India’s Greatest Contributions To Science.
Happy Independence Day India!
I did two historical sketches this week for my geometry class. One is the construction exercises from book I of the Elements, and the other is mostly the corresponding solutions. It was fun and good exercise. I also gained a new appreciation for Euclid’s construction of equiangular parallelograms (Book I, Prop 44), which is suwheet.
Christopher Danielson gave a #globalmath presentation this week on the standards for mathematical practice. He presented an okay problem from Singapore math with a bit of a strained context, and made it 20x cooler by using it as a context to think about structure and algorithms.
Today, @Richard_Wade tweeted a neat math teacher resource, with a spiffy set of riddles featuring 3 unknown numbers. I thought about how to GeoGebrize them, because, you know, and then I realized that might be a neat context for the students to work on turning a method into an algorithm.
Beat the machine! John Henry lives!
So here’s the sketch. It randomly picks a riddle type from among four, and you can switch clues if you’re stuck. If you give it a try, I’d love to hear feedback on how it works, or what you think about Christopher’s ideas in this context. Please?
A baker friend proposed this challenge today. And for some reason I am convinced it is perfect for a Math Rage Comic. What do you think? Does it suggest the question strongly enough? (My kids say no.) I made about half of it using the rage builder.
This is over on 101qs.com. Please go there and ask your questions.
UPDATE: the actual cake from the problem.
Very simple sketch. This article (Dragging and Making Sense of Invariants in Dynamic Geometry, Anna E. Baccaglini-Frank, Mathematics Teacher, April 2012) proposed a simple construction and asked “What’s invariant?” I’m always trying to think about hooks for higher level HS & college courses, and wondered if this would work as an #anyqs. So I made a video and uploaded it to 101qs.com.