To extend the idea of perpendicular bisectors and circumcenters of triangles, I designed a coordinate geometry activity. Feel free to use this activity. Exploring with the circumcenter
I will re-post with a summary of the class activity.
Objective:
Use coordinate geometry as a method for finding the intersection of
perpendicular bisectors of a triangle, the circumcenter. Write the equations of the lines of the
perpendicular bisectors of sides of a triangle.
Use the circumcenter to write the equation of a circle that is
circumscribed about the given triangle.
This activity was great. It was a perfect extension. I liked that I gave students the freedom to use their devices in class. They were not completely competent in using midpoint, distance, or equation of a line formula. But they could quickly search for the formula and look at an example of how to do the formula. (Which they have learned but have not practiced, thus forgotten.) Students needed a bit more than 50 minutes to complete, an hour would have afforded the majority of the class the time to successfully complete. As it was, only one class was completely successful by the end. I would use this activity again in class!
ReplyDeleteStephanie,
ReplyDeleteThanks for sharing your Exploring with the circumcenter activity. I just was informed that I am not scheduled to teach Geometry next year :(. I will have to hold onto this activity in hopes that I will teach Geometry in the near future.
I created an activity using Geometers Sketchpad to introduce my students to basic Geometry Constructions. You can view the lesson on youtube, https://www.youtube.com/watch?v=J322T3nVXnM
Thanks for Sharing!
Eileen