Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: Trisection
Replies: 19   Last Post: Feb 11, 2012 9:59 AM

 Messages: [ Previous | Next ] Topics: [ Previous | Next ]
 mark Posts: 206 Registered: 12/6/04
Re: Trisection
Posted: Jul 18, 2002 1:44 PM

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.

Steve:

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.

Mark.

Date Subject Author
6/20/02 Guest
7/3/02 Jacques
7/3/02 John Conway
7/3/02 mark
7/3/02 John Conway
7/3/02 Eric Bainville
7/3/02 John Conway
7/15/02 mark
7/16/02 mark
7/16/02 Rouben Rostamian
7/17/02 Eric Bainville
7/17/02 Steve Gray
7/18/02 mark
7/19/02 Eric Bainville
7/21/02 Steve Gray
7/22/02 Rouben Rostamian
7/23/02 mark
7/24/02 mark
7/19/02 Steve Gray
2/11/12 JO 753