Sharing Catriona Shearer’s geometry puzzles with my younger son – part 12

Catriona Shearer posted a really nice geometry puzzle today:

The rectangles are congruent, each with area 9. What’s the area of the triangle? pic.twitter.com/zNveRzcpTq

— Catriona Shearer (@Cshearer41) April 24, 2020

I thought this one would be a good challenge for my son and he was able to solve it, though he had a few false starts. He explains his thought process from start to finish here:

After he finished his explanation I had him look at the twitter thread and he liked the solution from M B Patey:

pic.twitter.com/DHqpw1Fpdw

— M B Patey (@mbpatey) April 24, 2020

Here he explains that solution and why he liked it:

I feel like a broken record, but I love these problems. Today’s was at exactly the right level for my son and made for a great project!