Math Monday came early this week, and we had some fun exploring Reuleaux triangles. Next to a circle, they’re the simplest curve of constant width you can make — that basically means you can roll a plank on top of them as smoothly as on wheels. The kids didn’t expect that one! (They also would make great manhole covers!)
Although they roll very smoothly, they do tend to wobble around a bit, so I built a little gutter on the plank to make it easier for the kids to experiment with. It was a quick project, and lots of fun for the kids. You don’t have to use a band saw or even the sander; all you really need is a jigsaw or coping saw, some scrap wood, and some nails.