An Exploration of
Triangle Concurrency

Teacher Notes

This exploration of triangle concurrency was written by four high school mathematics teachers during the University of Minnesota's Geometry Center 1996 Summer Teachers Institute. We designed this interactive web-based exploration tool to facilitate the teaching of triangle concurrency, both as an integral part of a geometry curriculum, and as enrichment material. This information can be used by individual students as a computer exploration, as classroom demonstration material, or as an alternative to a more traditional investigation of triangle congruency topics.

This exploration uses Key Curriculum's Geometer's Sketchpad as the principal dynamic geometry tool. These pages require access to the software GeometerŐs Sketchpad and a web browser capable of supporting the graphics. The files can be adapted to work for Cabri Geometry by downloading the html files and making some minor changes in the code and then creating the companion sketches in Cabri to replace the *.gsp and *.gss files. We have included a number of built in interactive sketches and have also added answers to questions posed in the investigations sections.

Your students will be better able to move through this material if they are familar with these topics.

They will also benefit from some prior exposure to the Geometer's Sketchpad and a web browser. These apecific computer skills will help their journey the the web go smoothly.

We have included periodic teacher checkpoints throughout the material, but have been purposefuly vague on the specific "teacher directed activites." This will require that you decide in advance how you want to collect data and record their investigations. We have deliberately left out instructions to students about assessment issues. We felt that each teacher has their own system, so we have included reminders to check with the teacher about specfic requirements. Some of the systems that could be used with these materials are...

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