Where does “двадцатипятиугольник” come from?

двадцатипятиугольник (Russian) comes from Russian двадца́ть, from Russian два, from Old East Slavic дъва, from Proto-Slavic dъva, from Proto-Balto-Slavic duwō, from Proto-Indo-European dwóh₁ — two.

двадцатипятиугольник (Russian): icosipentagon, 25-sided polygon

Definitions

  1. icosipentagon, 25-sided polygon

Ancestry of “двадцатипятиугольник”, step by step

двадцатипятиугольник traces back through 3 separate lines of ancestry.

via Russian двадца́ть

StepLanguageWordMeaning
1Russianдвадца́тьtwenty (20)
2Russianдваtwo
3Old East Slavicдъваtwo
4Proto-Slavicdъvatwo
5Proto-Balto-Slavicduwōtwo
6Proto-Indo-Europeandwóh₁two

via Russian у́гол

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

via Russian пять

StepLanguageWordMeaning
1Russianпятьfive; second-person singular imperative...
2Old Church Slavonicпѧтьfive
3Proto-Slavicpętьfive
4Proto-Indo-Europeanpénkʷefive
Every word from Proto-Indo-European dwóh₁Every word from Proto-Balto-Slavic duwōEvery word from Proto-Slavic dъva