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A Regular Nonagon

Date: 11/2/95 at 21:51:39
From: Anonymous
Subject: Is there a regular nonagon

I want to know if there is such a thing as a regular nonagon and 
if not, why can't you get one?

I've tried by using "triangle paper" and using lots of different 
angle measures and side lengths (trial and error) and haven't 
gotten a regular nonagon yet. I'd like to know if I just haven't 
tried hard enough and there is one, or if it is non-existing.

Please e-mail me at
Thanks- Tucker Hottes

Date: 11/5/95 at 16:29:21
From: Doctor Jeremy
Subject: Re: Is there a regular nonagon

There is such a thing.  As a matter of fact, for any whole number 
that is three or greater, you can find a regular polygon with that 
many sides.

The problem you had with getting a regular nonagon is that the 
regular nonagon has a weird angle between the sides.  The angle 
between each of the segments of the regular nonagon is 140 degrees 
(measured from the inside).  Triangle paper is designed to work 
with lots of angles like 30, 60, 90 degrees and so on.  140 isn't 
one of them.  I'm not sure how you would draw one, at least using 
such tools.  You probably could get one on a computer.

But yes, it does exist.  It's just very hard to draw.

-Doctor Jeremy,  The Geometry Forum

Associated Topics:
High School Geometry
High School Triangles and Other Polygons

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