Where does “trirectangular” come from?

trirectangular (English) comes from English tri, from Proto-Indo-European tréyes — three.

trirectangular (English): Having three right angles

Definitions

  1. Having three right angles

Ancestry of “trirectangular”, step by step

trirectangular traces back through two separate lines of ancestry.

via English tri

StepLanguageWordMeaning
1Englishtritriathlon; triangle
2Proto-Indo-Europeantréyesthree

via English rectangular

StepLanguageWordMeaning
1EnglishrectangularHaving a shape like a rectangle; Having axes that...
Every word from Proto-Indo-European tréyes →Every word from English tri →