A difficult geometry puzzle with an elegant solution.
Practice more problem-solving at https://brilliant.org/3b1b
Solution to the puzzle mentioned at the end: https://brilliant.org/3b1bindicator/
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A different write-up of this solution:
1992 Putnam with this problem:
A problem with a similar flavor came up on the 2005 Putnam A6. Give it a try! In the solutions for that problem, by the way, the that Calvin Lin is a friend of mine who works at Brilliant.
Music by Vincent Rubinetti: https://soundcloud.com/vincerubinetti/
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