Saw this interesting recommendation from Kate Nowak on Twitter last week:

The book (and some extra patty paper) arrived today and it looks like it has some great activities. I found one that seemed fairly easy to implement and gave it a shot with both kids. The project is a little lesson about the perpendicular bisectors in a triangle.

I tried it out first with my older son. We’ve just finished studying Art of Problem Solving’s *Introduction to Geometry* book which means that he’s seen a little bit about perpendicular bisectors before. He recognizes pretty quickly what he needs to do to make the project work, so we moved fairly quickly. Based on how this project went, I’m pretty excited about reviewing some more geometry concepts with him using this book.

My younger son has not had much geometry and I’m pretty sure has not heard the term “perpendicular bisector” before. I thought this project would still be interesting for him, though, because of the surprising result that the three perpendicular bisectors intersect in a single point. We went through the project a little slower than my older son’s pace, but he seemed to really enjoy it. He even wanted to try out a second triangle.

I was glad that he wanted to look at another triangle because that gave us a chance to try a triangle that wasn’t a right triangle. His interest and engagement in the overall project left me pretty excited to try teaching him some new geometry using the approach in the book.

So, I’m really happy with how this project went with both kids. Looks like this book gives you a great opportunity to review and to learn new geometry. Can’t wait to try out a few more of these explorations. Thanks to Kate Nowak for this awesome recommendation!