Dynamic Geometry Problem 1446: The Lemoine Line

Tangents to the circumcircle of triangle ABC, at points A, B, and C, meet sides BC, AC, and BA at points E, F, and D, respectively. Then E, F, D are collinear and line DEF is called the Lemoine line of triangle ABC.


Static Diagram of the Lemoine Line

Geometry Problem 1446: Lemoine Line. Using GeoGebra


Poster of the Lemoine Line using iPad Apps

Poster of Lemoine Line Using iPad

 

Classroom Resource:
Interactive step-by-step animation using GeoGebra

This step-by-step interactive illustration was created with GeoGebra.

  • To explore (show / hide): click/tap a check box.
  • To stop/play the animation: click/tap the icon in the lower left corner.
  • To go to first step: click/tap the "Go to step 1" button.
  • To manipulate the interactive figure: click/tap and drag the blue points or figures.

GeoGebra is free and multi-platform dynamic mathematics software for all levels of education that joins geometry, algebra, tables, graphing, statistics and calculus application, intended for teachers and students. Many parts of GeoGebra have been ported to HTML5.

Recent Additions

Geometry Problems
Open Problems
Visual Index
Ten problems: 1411-1420
All Problems
Triangle
Circumcircle
Circles
Circle Tangent Line
Classical Theorems
Dynamic Geometry
Collinear Points
GeoGebra
HTML5 and Dynamic Geometry
iPad Apps
View or Post a solution