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Re: Consturction of 17-sided regular polygon
Posted:
Jan 31, 1999 9:05 AM
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On Sun, 31 Jan 1999, Peter Hung wrote:
> I have trying to find out the procedure for constructing a regular 17-sided
> polygon.
The neatest construction I know is due to Richmond - I call it the
"quadruple quadrisection constriction":
1) quadrisect the perimeter of the circle, by points N,S,E,W;
2) quadrisect the radius ON by the point A;
3) quadrisect the angle OAE by the line AB;
4) quadrisect the straight angle BAC by the line AD:
N
I |
| J
C |
F
A
|
W---------G-D-O-B-----H-----E
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S
5) draw the semicircle DFE, cutting ON in F;
6) draw the semicircle GFH, centred at B;
7) cut the semicircle WNE by the perpendiculars GI and HJ to WE.
Then I and J are points of the regular heptakaidecagon on the
circle ENWS that has one vertex at E.
John Conway
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