Table of Contents

Phase 2 - In Orbit

The Language of Triangles

Teacher Notes

1. This activity should be completed in pairs.

2. The suggested completion time is 30-45 minutes.

3. The display can form the basis for assessment. Criteria should include:

   • a. Accuracy in construction
   • b. Correct identification of triangles
   • c. Use of precise and accurate terminology in the descriptions.
     
     

4. An assessment rubric accompanies this activity.

The Language of Triangles

As a Junior Space Explorer, you learned that triangles can be identified according to the measures of interior angles and the lengths of the sides. Now it's time to communicate your knowledge using correct mathematical language.

You will be working with a partner.

Materials:

• plasticine/modelling clay or miniature marshmallows
• drinking straws
• scissors

Procedure:

1. For the first part of this activity, make sure your partner cannot see the triangles you are constructing.

2. Using drinking straws and either the clay or marshmallows, form 4 triangles. Use a marshmallow or blob of clay to attach three straws together. To vary the side lengths, use scissors to cut the straws.

3. Get together with your partner, keeping all triangles out of sight.

4. Take turns describing each one of your triangles by its characteristics: no sides equal, 2 congruent sides, 3 congruent sides, 3 acute angles, 1 right angle, 1 obtuse angle etc.

5. When you or your partner correctly guesses the kind of triangle being described, show it. Continue until you and your partner have described and guessed all 8 triangles created.

Questions:
What clues did you give your partner to help identify the triangles?

Conclusion:
Display your 8 triangles. Together, label each one by name and, using accurate mathematical language, describe each triangle.

Assessment Rubric