• Matrix Transformations in GeoGebra

    by  • August 6, 2013 • Math • 1 Comment

    Todd & Jen CLast weekend I had the great pleasure of learning about matrix transformations in GeoGebra from the incomparable Todd Edwards! He was one of the organizers, along with Steve Phelps, of the 2013 North American GeoGebra Conference, held on the beautiful Miami University campus, in Oxford, OH. (I’ll write more about that soon.)

    I attended this session, in part, because my tweep, Barbara, passed on a query from my tweep, Pam, and I wanted to know the answer! Todd was pinch-hitting for a missing presenter, and he showed us enough about matrices to get me started.


    On our long drive home, I made these:

    A traditional activity in which a triangle is transformed by matrix multiplication.

    A nontraditional activity in which a parabola is transformed by matrix multiplication.

    What do you think?


    After teaching for 14 years, I now design curriculum and create digital and print instructional materials for high school and middle school math. I have also invented and am now marketing radian-scale protractors. Check out www.proradian.net! I'm very happily married and have 2 grown sons and a cat named Louie.

    One Response to Matrix Transformations in GeoGebra

    1. August 20, 2013 at 11:30 am

      Hi Jen:
      As I promised way back during one of the #globalmath conferences that I will check these Geogebra files and give you some feedback.

      Here I am and I like both files and I assume that the difference between the traditional and non-traditional is the fact that the non-traditional is dealing with more of an Algebra take on transformations rather than the usual geometric shapes students traditionally encounter in Geometry, correct?

      I use Geogebra but not as much as I use Geometer’s Sketchpad and I do not recall ever using matrices within Sletchpad. So, you have initiated a challenge for me to try to implement matrices within Sketchpad. Thank you

      Is there a way to set either file to have “what if” situations whereby students would have to make some predictions before Geogebra allows certain items to appear and divulge the answers? Just curious.

      Thank you and take great care! 🙂


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