Where does “pentadecagon” come from?

pentadecagon (English) comes from English gon, from Ancient Greek γωνία, from Ancient Greek γόνυ, from Proto-Hellenic gónu, from Proto-Indo-European ǵónu — knee.

pentadecagon (English): A polygon with fifteen sides

Definitions

  1. A polygon with fifteen sides

Ancestry of “pentadecagon”, step by step

pentadecagon traces back through two separate lines of ancestry.

via English gon

StepLanguageWordMeaning
1EnglishgonOne hundredth of a right angle; a gradian;...
2Ancient Greekγωνίαcorner, angle; joiner's square; cornerstone
3Ancient Greekγόνυknee
4Proto-Hellenicgónuknee
5Proto-Indo-Europeanǵónuknee

via French pentadécagone

StepLanguageWordMeaning
1Frenchpentadécagonepentadecagon
Every word from Proto-Indo-European ǵónuEvery word from Proto-Hellenic gónuEvery word from Ancient Greek γόνυ
pentadecagon — Etymology, Origin & Word History | Etymology Explorer