The word "triangle", though taken for granted, can be easily taken apart and etymologized under scrutiny. However, rarely do we peruse this triple-sided figure. Triangle is a loanword from French, where the word in turn derived from the Latin word triangulum. This was a neuter of the adjective triangulum. This is where the obvious combination of tri- "three" and angulum "angle" occurred. The prefix tri- is often overlooked in the grander etymology of this word, but it is nevertheless important and interesting. It comes from the Latin word tres (the etymon of three) and this came from Greek tria "three", from the PIE cognate trei. Angulum is a little less convoluted in its history, but has some interesting cousins. It can be traced back to the Proto-Indo-European word angh, or "to bend". This is related to the word angh, which was covered in yesterday's post about anger, since something bent can become "constricted", the definition of the latter PIE word. Next time you get frustrated by geometry, appreciate the irony.
Adam Aleksic, a freshman studying linguistics at Harvard University, has been described as the internet's sixth most famous etymologist. He has disturbing interests in words, vexillology, geography, board games, limericks, and law, and he loves writing about himself in the third person.
The Etymology Nerd