Drexel dragonThe Math ForumDonate to the Math Forum


Math Forum
 Ask Dr. Math
 Discussions
 Internet Newsletter
 MathTools
 Problems of the Week
 Teacher2Teacher
 Teacher Exchange
 Workshops

Search All of the Math Forum:
Browse our Internet Mathematics Library

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


Math Forum » Discussions » Math Topics » geometry.pre-college.independent

Topic: circumference in degrees of a triangle
Replies: 10   Last Post: Nov 22, 2003 11:36 PM

Advanced Search
Reply to this Topic Reply to this Topic

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
me@talmanl1.mscd.edu

Posts: 1,815
Registered: 12/6/04
Re: circumference in degrees of a triangle
Posted: Nov 22, 2003 11:36 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Jim Totten wrote:

> Here's a question:
> Can you, leaving your Parallel Postulate at home, and going for a walk
> around a triangle, PROVE that its interior angles add to 180?

No--and neither can anyone else--unless you allow some equivalent of the
Parallel Postulate. The condition that the sum of the interior angles
of some triangle be 180 degrees is itself an equivalent of the Parallel
Postulate.

--Lou Talman
Department of Mathematical & Computer Sciences
Metropolitan State College of Denver

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2013. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.