The Putnam Exam has legendary difficulty: the average (median) score is usually 1 out of a possible 120 points. No calculators allowed though, and you have to prove everything very carefully. This geometry problem appeared on one of the tests, and there is a neat way to solve it!

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Kyle
Professor X
Richard Ohnemus
Erik J. (for spotting multiple errors in my posts!)

Sources
https://mks.mff.cuni.cz/kalva/....putnam/psoln/psol787
https://iastate.app.box.com/s/....r8zqykcivi84tftyy8j5

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