Drexel dragonThe Math Forum

The Math Forum Internet Mathematics Library

The Euler Number (Geometry and the Imagination)

Library Home || Full Table of Contents || Library Help

Visit this site: http://geom.math.uiuc.edu/docs/education/institute91/handouts/node29.html

Author:Conway, Doyle, Gilman, Thurston; The Geometry Center
Description: If we have a polyhedron, we can compute its Euler number, x=V-E+F. In fact, we computed Euler numbers ad delectam. Why did we do this? One reason is that they are is easy to compute. But that is not obviously a compelling reason for doing anything in mathematics. The real reason is that it is an invariant of the surface (it does not depend upon what map one puts on the surface) and because it is connected to a whole array of other properties a surface might have that one might notice while trying to describe it. One easy example of this is Descartes' formula...

Levels: High School (9-12), College
Languages: English
Resource Types: Lesson Plans and Activities
Math Topics: e, Differential Geometry

[Privacy Policy] [Terms of Use]

Home || The Math Library || Quick Reference || Search || Help

© 1994- The Math Forum at NCTM. All rights reserved.