I’ve been binge listening to math podcasts lately. In one – and, sadly, I don’t remember which one! – I heard a neat problem about triangles. Last night Paula Beardell Krieg shared Suzanne von Oy’s blog post which reminded me of the problem:
After seeing von Oy’s post I threw together some shapes from the puzzle and set them to print overnight. This morning I went through the puzzle with both kids.
Here’s the puzzle: You have triangles with sides 5-5-6 and 5-5-8. Which one has the larger area?
My older son went first:
My younger son went second – my older son has much more experience with geometry so I thought having them work separately would be better.
I think this is a great puzzle / problem for kids learning geometry.
Mike's Math Page 
It might be interesting to pursue the “true in general” thought and derive the area as a function of the third side length (the first two sides being 5).