Thread:TSRITW/@comment-33431934-20200211033809/@comment-33431934-20200211035848

cos72° = Half the golden ratio

sin72° = [√(10+2√5)]/4

The area of a pentagon is based on the sin, not cos.

But...

sin18° = Half the golden ratio

cos18° = [√(10+2√5)]/4

360/18 = 20

So the golden ratio could be the area of a much simpler icosagon.