This past Spring my younger son did a really fun geometry review by studying some of Catriona’s geometry puzzles. I think we did around 20 projects – they can be found here:

20 or so projects is only scratching the surface, though, since she comes out with fantastic geometry puzzles all the time! The one from yesterday is fantastic and I thought it would be great for another project for my son:

His solution to the problem was computational. He explains the main ideas here without going into all of the computational details:

In all of our projects we return to the problem’s twitter thread and my son picks out a solution that he thinks is interesting. Today he picked the solution from @lucythepoet

Consider red-yellow as a unit, we have 3 units on top and 1 unit on the bottom. Everything's similar, so scaling the length of a unit by 3 also scales the height by 3. So green:blue is a 1:3 ratio Similarly, each red-yellow block is also a 1:3 ratio

Here’s his explanation of this solution and a bit about why he liked it:

I think – and have thought for a long time! – that Catriona’s puzzles are great to use with kids. The process of attempting to solve the puzzle (sometimes getting it, sometimes not) and then going to the twitter thread to see all of the neat solutions has been a great way for my younger son to review geometry.