Points of Concurrency Lab

This week we started talking about points of concurrency in my Honors Geometry class.  We talked about the definitions of Incenter, Circumcenter, Centroid, and Orthocenter.  

In the past I have had my students construct these points of concurrency the  "old fashioned way" with a compass and straight edge.  Since my students usually don't have the world's best compass, we ran into problems with the accuracy of our constructions.    This year I decided to mold most of these constructions around the "Geometry Constructions Tutor Lite" App.  We were able to accurately construct an Incenter and Circumcenter using the app.  The vast majority of my students were able to construct their figures accurately.  We were able to have a discussion that connected the types of triangles and where the points of concurrency were located.

For our discussion of the centroid, I had my students draw their medians on a triangular piece of cardboard.  They were then able to discover that the centroid is the exact balance point of the triangle.  They were very excited to be able to balance their triangles on one finger.

Overall, I think the lesson went pretty well.  It allowed students to use technology and also do some hands-on work.  It was the best of both worlds!