Drexel dragonThe Math ForumDonate to the Math Forum

Ask Dr. Math - Questions and Answers from our Archives
_____________________________________________
Associated Topics || Dr. Math Home || Search Dr. Math
_____________________________________________

Sixteen-sided Window


Date: 08/05/97 at 23:56:14
From: Robert Richards
Subject: Lengths of a sixteen-sided circle

I am trying to cut a window for my twin girls' playhouse and would 
like to make a sixteen-sided window to go in the second floor hallway. 
I have tried to lay it out on cardboard using about every increment I 
can calculate for the total but it still doesn't work out. Can you 
help me out so I can tell where I am going wrong?


Date: 08/12/97 at 13:22:10
From: Doctor Rob
Subject: Re: Lengths of a sixteen-sided circle

You want the length of the side of a regular 16-sided polygon, right?

Draw a circle of diameter d.  Pick a point on the circle to be the
starting point.  Mark off points around the circle at regular 
intervals, to be connected up to make your 16-gon.  You want to know 
what the length of these sides will be.

The answer is d*Sqrt[2 - Sqrt[2 + Sqrt[2]]]/2.  This is approximately
0.19509*d.  The central angle that each side corresponds to is 22.5
degrees.

-Doctor Rob,  The Math Forum
 Check out our web site!  http://mathforum.org/dr.math/   
    
Associated Topics:
High School Geometry
High School Practical Geometry
High School Triangles and Other Polygons

Search the Dr. Math Library:


Find items containing (put spaces between keywords):
 
Click only once for faster results:

[ Choose "whole words" when searching for a word like age.]

all keywords, in any order at least one, that exact phrase
parts of words whole words

Submit your own question to Dr. Math

[Privacy Policy] [Terms of Use]

_____________________________________
Math Forum Home || Math Library || Quick Reference || Math Forum Search
_____________________________________

Ask Dr. MathTM
© 1994-2013 The Math Forum
http://mathforum.org/dr.math/