Where does “семиугольник” come from?

семиугольник (Russian) comes from Russian у́гол, from Proto-Slavic ǫgъlъ, from Proto-Balto-Slavic *ángulas, from Proto-Indo-European h₂engulos, from Proto-Indo-European h₂eng- — curve, bend.

семиугольник (Russian): heptagon

Definitions

  1. heptagon

Ancestry of “семиугольник”, step by step

семиугольник traces back through two separate lines of ancestry.

via Russian у́гол

StepLanguageWordMeaning
1Russianу́голangle; corner
2Proto-Slavicǫgъlъcorner, angle
3Proto-Balto-Slavic*ángulas—
4Proto-Indo-Europeanh₂engulosjoint?
5Proto-Indo-Europeanh₂eng-curve, bend

via Russian семь

StepLanguageWordMeaning
1Russianсемьseven
2Proto-Slavicsedmьseven
3Proto-Indo-Europeanseptḿ̥seven
Every word from Proto-Indo-European h₂eng- →Every word from Proto-Indo-European h₂engulos →Every word from Proto-Balto-Slavic *ángulas →