Equilateral
Pronunciation: /ˌi kwəˈlæ tər əl/ ?
A polygon
whose sides are the same length is called equilateral.^{[1]} The
most commonly used equilateral polygon is the
equilateral triangle.
An equilateral quadrilateral is a parallelogram with equal sides. If the adjacent sides
of an equilateral quadrilateral are
perpendicular,
the shape is a
square.
All
regular polygons
are equilateral.
The word equilateral is derived from Latin. Equi is taken from the word aequus,
meaning 'equal'. lateral is taken from the word lateralis, meaning 'of the side'.
Click on the blue points in manipulative 1 and drag them to change the figures. No matter
how you change these figures, they remain equilateral.
Examples
 Manipulative 1: Equilateral figures. Created with GeoGebra. 

References
 equilateral. http://wordnet.princeton.edu/. WordNet. Princeton University. (Accessed: 20110108). http://wordnetweb.princeton.edu/perl/webwn?s=equilateral&sub=Search+WordNet&o2=&o0=1&o7=&o5=&o1=1&o6=&o4=&o3=&h=.
 Carol Vorderman. Math Dictionary , pg 38. DK CHILDREN, July 20, 2009.
More Information
 McAdams, David. Equilateral Triangle. allmathwords.org. All Math Words Encyclopedia. Life is a Story Problem LLC. 20090312. http://www.allmathwords.org/article.aspx?lang=en&id=Equilateral%20Triangle.
 McAdams, David. Polygon. allmathwords.org. All Math Words Encyclopedia. Life is a Story Problem LLC. 20090312. http://www.allmathwords.org/article.aspx?lang=en&id=Polygon.
Printed Resources
Cite this article as:
Equilateral. 20100125. All Math Words Encyclopedia. Life is a Story Problem LLC. http://www.allmathwords.org/en/e/equilateral.html.
Translations
Image Credits
Revision History
20081213: Added derivation of word from Latin (
McAdams, David.)
20081118: Changed manipulative to GeoGebra. Added sentence on polygons (
McAdams, David.)
20080716: Added vocabulary links (
McAdams, David.)
20080607: Corrected spelling (
McAdams, David.)
20080510: Initial version (
McAdams, David.)