La Hire's Theorem in Ellipse: What Is It About?
A Mathematical Droodle


This applet requires Sun's Java VM 2 which your browser may perceive as a popup. Which it is not. If you want to see the applet work, visit Sun's website at https://www.java.com/en/download/index.jsp, download and install Java VM and enjoy the applet.


What if applet does not run?

Explanation

|Activities| |Contact| |Front page| |Contents| |Geometry| |Eye opener|

Copyright © 1996-2018 Alexander Bogomolny

La Hire's Theorem in Ellipse

The applet suggests the following theorem:

  Let there be two points A and B outside an ellipse. From points A and B draw tangents AC, AD, BE, BF to the ellipse. Then if B lies on CD, then A lies on EF.


This applet requires Sun's Java VM 2 which your browser may perceive as a popup. Which it is not. If you want to see the applet work, visit Sun's website at https://www.java.com/en/download/index.jsp, download and install Java VM and enjoy the applet.


What if applet does not run?

This is just another illustration of a theorem valid for all non-degenerate conics.

Poles and Polars

Conic Sections > Ellipse

|Activities| |Contact| |Front page| |Contents| |Geometry| |Eye opener|

Copyright © 1996-2018 Alexander Bogomolny

71471154