# Clip 9/18: Lesson Part 2A

## Overview Download Transcript (PDF)

Hillary Lewis continues her formative re-engaging lesson on classifying triangles by distributing a task, “Dividing Shapes into Triangles.” She asks the students to take out pencils and rulers, and use both to draw lines within the shapes to make triangles, and then label the triangles.

After they get started, Hillary challenges them to use the square and rectangular frames to create particular kinds of triangles: “If you made a right isosceles triangle in one shape, can you make it in another one?”

## Teacher Commentary

**Hillary Lewis**

Since we were categorizing, looking for and making use of structure was one of the things we were looking at. We also had straight edges, rulers out, in terms of using tools strategically.

During the conversation during that lesson, they were able to construct viable arguments and critique the reasoning of others. I was very fortunate the teacher had worked with this class regarding how to speak respectfully to one another.