Equilateral, Isosceles, Scalene - Word Origins
Date: 12/09/2001 at 14:45:26 From: Julian Subject: Triangle history I need to find out about the origins of the scalene, isoceles, and equilateral triangles. How they were named? Why were they named that?
Date: 12/09/2001 at 15:12:56 From: Doctor Sarah Subject: Re: Triangle history Hi Julian - thanks for writing to Dr. Math. From Steven Schwartzman's _The Words of Mathematics - An Etymological Dictionary of Mathematical Terms Used in English_ (Mathematical Association of America): equilateral (adjective): from Latin aequus "even, level" and latus, stem later-, "side," both of uncertain origin. Related borrowings from Latin are bilateral and multiplateral. In geometry an equilateral triangle is one in which all sides are equal in length. isosceles (adjective): from Greek isos "equal," of unknown prior origin, and skelos "leg." The Indo-European root (s)kel- "curved, bent" is found in scoliosis and colon, borrowed from Greek. In geometry, an isosceles triangle or trapezoid has two equal legs. It may seem strange that the root means "bent" even though the sides of a triangle and a trapezoid are straight, but each leg is bent relative to the adjoining legs. scalene (adjective): from the Indo-European root skel- "to cut." Greek skalenos originally meant "stirred up, hoed up." When a piece of ground is stirred up, the surface becomes "uneven," which was a later meaning of skalenos. A scalene triangle is uneven in the sense that all three sides are of different lengths... - Doctor Sarah, The Math Forum http://mathforum.org/dr.math/
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