Day 10: Special Segments and Triangle Inequality

We did an entire unit today. It started out with looking at midsegments and then we moved to perpendicular bisectors, angle bisectors, medians, altitudes, and all those fun centers that go along with the points of concurrency. I had done this awesome discovery activity when I student taught where it takes you through determining if the segments have a point of concurrency and all those equidistant things, but I couldn’t find it anymore. I searched for some ideas online but couldn’t find anything I liked that much. I didn’t think to email my old Geometry co-op until typing this out…maybe I can get it for next time. But we did go through what some of those relationships were and had fun drawing all the segments, using different colors and everything.

I also did a discovery activity for the inequalities in triangles. To see that the sum of two sides have to be better than the third, I had the kids use stick pretzels to test it. The only issue is that when they get to the one where the sum of two sides equals the third (which shouldn’t work) a lot of the kids don’t follow it close enough to make sure the two pretzels are really exactly the same size. Because of the error with that, a lot of times you have to go through that set again with students. I had some pasta sticks on hand for that purpose because it’s a little easier to see (but definitely not as fun to eat). Here’s the file:

I also had some kids turn in their Swan Challenge. It’s all about finding angle measured in this really complicated swan picture. Takes a lot of focus but it’s actually not too difficult once you get on a roll. Really more about perseverance. Here it is if anyone wants it:

Quelquefois, je pense de quelque chose un peu tard, mais c’est pas grave. Mes étudiants apprennent encore.