Part 4 of Sharing Catriona Shearer’s geometry puzzles with my younger son

I’ve been sharing some of Catriona Shearer’s geometry puzzles with my younger son lately. The idea is for him to try to solve the problem and then explain a solution from the twitter thread about the problem.

The puzzle we looked at today was posted by Shearer on April 10th:

Watching him work through the solution is a great example of what a kid learning math looks like. His approach is very computational – sometimes the calculations can sort of overwhelm the geometry ideas for kids and that’s sort of what happens here:

The solution from the twitter thread that he liked was from Brenda Meshejian

He does a nice job of explaining this solution: