Etymology of the Word Rectangle

Date: 02/07/2003 at 18:57:04
From: Antoinette
Subject: Rectangles

Where does the word "rectangle" come from?

Date: 02/08/2003 at 11:18:52
From: Doctor Sarah
Subject: Re: Rectangles

Hi Antoinette - thanks for writing to Dr. Math.

From Steven Schwartzman's _The Words of Mathematics - An Etymological 
Dictionary of Mathematical Terms Used in English_ (1994, Mathematical 
Association of America):

rectangle (noun), rectangular (adjective): 
from Latin rectangulus "right-angled," a literal translation of Greek 
orthogonios. The first component is from Latin rectus "straight, 
upright, perpendicular," from the Indo-European root reg- "to move in 
a straight line"; the second component is angle. In older English 
usage, rectangle meant "a right angle." In modern usage, a rectangle 
is a quadrilateral in which every adjacent pair of sides is 
perpendicular; in other words, all four angles are right angles.

- Doctor Sarah, The Math Forum
  http://mathforum.org/dr.math/