Pentagon pleasure

Two regular pentagons. The centre of the large one is a vertex of the small one. What is yellow : green?

Scroll down for a solution to this problem.


Yellow : green is 1 : 1.

Solution using generalized angle bisector theorem.


Please find here the video solution: Video: Pentagon pleasure.

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2 replies on “Pentagon pleasure”

It is a shame that there is no link here to all the interesting approaches which were found to this problem, and now exist only in the Twitter/X feed of replies to the problem there.

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