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Solution of the Week #360 - Isosceles Nine-Point Circle part 2

April 11, 2022 Elliott Line

The angle at the apex will be 72 degrees.

The two longer lengths are two sides of a regular pentagon, and the six shorter sides are sides of a regular decagon.

The ration of long length to short length is sin(36)/sin(18) = sqrt(1/2(5+sqrt5)) ~ 1.902…

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