Triangle properties

I tried to use workstations and have students investigate different triangle properties: isosceles triangle base angle theorems, exterior angle theorem, and correspondence of angle length to side length. These investigations came from the Discovering Geometry book and included using compass, protractor, and patty paper.

The investigations went okay. I particularly liked the exterior angle theorem investigation and the correspondence of angle size to opposite side length. For whatever reason, students got bogged down with the two isosceles triangle base angle theorems (two congruent sides results in two congruent angles and the converse).

I was expecting these investigations to go quicker than they did. After collecting sheets to see what students captured, it appeared that many of them did not pick up on key properties. I have to hope that as we continue to work with these properties that they will make sense. I intend to keep referencing back to these investigations, which I hope will reinforce the importance of making sense of what is happening during an investigation.

I intend to have students work through the exterior angle theorem and then complete an angle puzzle that a colleague found online.