The circles O and O_{1} intersect at A and B (see the figure above),
CD is the common external tangent, CA intersects circle O_{1} at E,
DA intersects circle O at F. If FC and
ED intersect at G, prove that GC and GD are congruent.
Dynamic Geometry of Problem 897
The interactive demonstration
below 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 multiplatform 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.
Home

Search  Geometry

Problems 
All Problems 
Open Problems

Visual Index

10 Problems

Problems Art Gallery

Art 
891900

Dynamic
Geometry

GeoGebra 
Circle

Intersecting Circles

Congruence

iPad Apps

Nexus 7 Apps
 Projects

Email

Solution/Comment  by Antonio Gutierrez
