Polygon Names II
Date: 12/11/2003 at 17:06:31 From: Laura Subject: Polygon Names For extra credit, my geometry teacher asked us to find out why the triangle is named "triANGLE", unlike all the other polygons, which have names like "quadriLATERAL" or "pentaGON". But I can't find any information about it.
Date: 12/12/2003 at 11:47:28 From: Doctor Peterson Subject: Re: Polygon Names Hi, Laura. Words don't always have good reasons behind them; but here are my ideas about it (which I found by searching our site for "triangle polygon name"): Polygon Names http://mathforum.org/library/drmath/view/57848.html There I suggest that the words "triangle" and "quadrilateral" were taken from Latin, while the others were taken from Greek at a different time when Greek was more popular. I've just done a little more research, and find that they actually all came from Latin, which pushes the question back a little. In Latin, as in English, there were both "native" Latin words and words borrowed from Greek: English Greek Latin borrowed Latin native ------- ----- -------------- ------------ triangle trigonon trigonum *triangulum quadrangle tetragonon tetragonum quadrangulum quadrilateral tetrapleuron *quadrilaterum pentagon pentagonon *pentagonum quinquangulum So when English started to be used in writing about mathematics, the Latin terms were borrowed; and presumably some of the preferred Latin terms were native Latin words (triangulum and quadrilaterum), and some were the Greek (pentagonium). So the same argument I made about English applies to the Latin: most likely the more common objects were usually called by their native Latin names, while the names for the objects most often discussed by scholars were taken from Greek, the language in which mathematics was written at the time. It's interesting that the Greek tetragonon usually meant "square", not just anything with four sides; that may be why the Latin "quadrilateral" is used instead of "tetragon" or "quadrangle" in English. Since Latin had not borrowed the Greek "tetrapleuron" that Euclid would have used, when Euclid was translated to English they would have used the native Latin "quadrilateral". If you have any further questions, feel free to write back. - Doctor Peterson, The Math Forum http://mathforum.org/dr.math/
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