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Topic: What do you call an 11 sided polygon?
Replies: 29   Last Post: Dec 27, 2006 6:37 PM

 Messages: [ Previous | Next ]
 Sarah Seastone Posts: 171 Registered: 12/3/04
Re: What do you call an 11 sided polygon?
Posted: Sep 20, 1995 5:01 AM

>What do you call an 11 sided polygon? Please respond via e-mail.
>
>rickw@ntn.com

An 11-sided polygon is called a hendecagon (or endecagon).

Here's some additional information contributed by John Conway in October of
1994:

1) For the "numerical" part of the name, one should use the Greek
prefixes:

mono, di, tri, tetra, penta, hexa, hepta, octa, ennea,

deca, hendeca, dodeca, trideca, etc, icosa, triaconta, hecta ..

10 11 12 13 20 30 100

A 24-gon would thus officially be an icositetragon.

There are variations in spelling and formation

(eg dekagon, endecagon, triskaidecagon,...)

(the "kai" here means "and")

The "gon" has an interesting etymology : it is ultimately
derived from the Greek word "gonu" for "knee", which they
transferred to "angle".

This word goes straight back to the Indo-European, and is
essentially the same in lots of languages:

gonu (greek)
genu (latin)
k nee (english)

French is similar to Latin here, and German to English (except
that the "K" is still pronounced.

3) The "hedron" in "polyhedron" is also an Indo-European
word, meaning "seat". A "cathedral" church is one that contains
a seat from which a bishop hands down authoritative opinions
(cata = down, hedron = seat).

In accordance with Grimm's law, the "h" is Greek
correesponds to "s" in English, while "d" may soften to "t"
and "p" or "b" to "f" or "v". So look:

penta
five hexa
six hepta
seven hedr
seat ped
foot

4) In summary, a "polygon" is a thing with many knees,
and a "polyhedron" a thing with many seats.
. . .

I see someone asked about the 24-gon, 48-gon, 96-gon. The
"official" names are

icositetragon

tetracontaoctagon

enneacontahexagon

if anyone cares. A "myriagon" would be a polygon with 10000 sides.

. . .

I see that
"undecagon" and "duodecagon" have been rearing their ugly
heads again. The full set is

monogon, digon, trigon, tetragon, pentagon, hexagon, heptagon, octagon

(of which monogon and digon can only be used in rather special circumstances);

it's digon not "bigon"; and trigon and tetragon are alternatives to "triangle"
and "quadrilateral" - the adjectival forms "trigonal" and "tetragonal"
being more common), then

enneagon, decagon, hendecagon, dodecagon, triskaidecagon, tetrakaidecagon,...

not

nonagon undecagon duodecagon

but tridecagon and tetradecagon (&c)
are OK.

________________
Sarah Seastone
Editor/Web Archivist
The Geometry Forum
sarah@forum.swarthmore.edu
http://forum.swarthmore.edu/~sarah/
_____________________________________

Date Subject Author
9/19/95 Brian Deacon
9/20/95 John Conway
11/20/03 TheHez
12/16/03 John Conway
1/25/05 jimmy
1/25/05 Bob L Petersen
12/17/06 ooooroseoooo
9/20/95 Sarah Seastone
9/20/95 Jim LaCasse
9/20/95 Robert Allen Saxon
9/20/95 Lou Talman
9/21/95 John Conway
9/21/95 Dan Hirschhorn
9/21/95 Chrystal Hogan
2/9/04 Terence Watters
9/21/95 brihut@cr520@cleveland.freenet.edu
9/21/95 brihut@cr520@cleveland.freenet.edu
9/21/95 brihut@cr520@cleveland.freenet.edu
9/22/95 John Conway
9/22/95 John Conway
8/25/97 r!chard tchen
1/19/04 Mr. Scott Sutow
1/20/04 Mary Krimmel
1/20/04 Carl LaCombe
1/21/04 Mary Krimmel
1/20/04 John Conway
9/21/06 laylalover
10/2/06 Brian Quincy Hutchings
12/27/06 Ed C.
12/18/06 sushi