Review properties of triangles by having students share the recordings they made in the previous session.
Invite students to the computer area and demonstrate how to create triangles using the Making Triangles Applet.
Guide students through the steps of clicking and dragging geobands to the geoboards to create triangles with three corners (angles). Remind students how to create a triangle on a real geoboard and that the number of sides of a triangle does not change.
Instruct students to create at least five different triangles and to copy these triangles on their Geoboards Activity Sheet.
Geoboards Activity Sheet
Specifically, you may ask students to create triangles with particular traits. Depending upon students' experiences with triangles, they could create triangles with:
- all 3 sides different lengths
- 2 sides the same length
- one right angle
Then students can record their examples on the Geoboards Activity Sheet.
Questions for Students
1. Can you tell me how many sides each triangle has?
[A triangle has 3 sides.]
2. Describe the different kinds of triangles you made. How are they alike? How are they different?
[They are alike because they all have different sides. They are different because they are different sizes. ]
- Which strategies worked well with the students? Which strategies did not work well?
- Which ideas did the students give you that will influence how you teach this lesson next time or reinforce the objectives of this lesson later in the school term as a review?
- What key vocabulary words did I use in the triangle lessons? Do students understand what these vocabulary words mean?"