Go Geometry Problems

Dynamic Geometry Problem 893: Triangle, Circumcircle, Incenter, Circle, Tangent, Collinear Points. GeoGebra, HTML5 Animation for Tablets (iPad, Nexus). Levels: School, College, Mathematics Education

The dynamic figure below shows a triangle ABC with incenter I. Circle of center C and radius CB intersects AC at D. Tangent to the circumcircle O intersects circle C at E. Prove that the points D, I, and E are collinear.
 

 

Dynamic Geometry of Problem 893
The interactive demonstration above was created with GeoGebra.

To stop/play the animation: tap the icon in the lower left corner.
To reset the interactive figure to its initial state: tap the icon in the upper right corner.
To manipulate the interactive figure: tap and drag points or lines.
  

GeoGebra
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. It has received several educational software awards in Europe and the USA.
 

Dynamic Geometry Problem 893: Triangle, Circumcircle, Incenter, Circle, Tangent, Collinear Points. HTML5 Animation for Tablets
 

 

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