Date: Jul 18, 2002 1:44 PM
Author: mark
Subject: Re: Trisection

Steve wrote:

> I just did a 5-minute check with Geometer's Sketchpad. In one
>iteration (original directions only) it didn't do too well. My angle
>was 75 degrees. My guess for placing D was BD/BA=0.292.
>The angle E'OB comes out to be 25.562 degrees, 2% high.
> I think my construction is correct because as the first guess
>approaches 25 degrees, the construction result does also.
> But I agree that further tweaks might make it much better.


I think there is something wrong with your construction.
I am assuming you were using 75 degrees as your unknown angle at point
A,(this is the original lettering), intended length AB=AC=1 and the
first guess radius from step 4 to be CD=.292 (I'm not sure why you
call it BD). My results using the above yield 24.996 deg.
Even if I do use BD=.292, (which is outside the first guess parameters
of the construction) I get 25.174 deg.

Please try again.