Review the previous lesson by encouraging students to recall the properties of triangles. Place the attribute triangles on tables for students to explore independently. This exploration helps satisfy the students’ curiosity and builds on their initial experiences with the properties of triangles. Invite students to ask questions of you and each other.
After students adequately explore the shapes, give them copies of the My Triangles activity sheet. Instruct them to work individually to trace the triangles printed on the sheet and then trace the attribute triangles found in the bag onto a blank sheet of plain copy paper.
Demonstrate how to hold the attribute block with one hand while tracing with the other. If students have difficulty with this task, they can work in pairs with one holding the triangle while the other draws, and then switching roles. To make tracing easier, students can also tape the attribute triangles to the paper or place the paper on top of a triangle that is taped to the table and use a crayon to rub over the triangle. After the students complete at least two tracings or rubbings of triangles, ask them to do free-hand drawings of triangles on another sheet of paper.
When students complete their drawings, have them look through books or magazines for triangles or have them sort collections of shapes that you have placed in bags.
To close this lesson, ask each student to identify a triangle in the room. Then have students share with the class where they found triangles and how they knew the objects were triangles.
