I’ve written before how I’m trying to keep a math notebook/journal of problems I’m working on, in an effort to develop a useful notebook keeping method for students. Today, I’m proud to announce what I think is the first solution to a non trivial problem in my notebook.
The question was one I got from James Tanton:
Find the minimum square that can enclose a 3-4-5 right triangle.
I’d worked on this problem for a while a few weeks ago, and then set the whole notebook aside. Tonight I came back to the notebook to try to work on a different problem, and then I flipped back to this problem and started to write out a few more notes, and pretty quickly saw how I could use trig to solve the problem. I’d say that’s a ringing endorsement of my problem notebook as a useful mathematical tool, and a great way to end the evening.