The group should be able to use a protractor to identify qualities of angles.
Setup Time: 15 minutes
Time: 35 – 45 minutes
Instruction: Whole class, pairs and Individual
1. Teachers should tape chart paper to the chalkboard. Students should lay their chart paper on the desk so it is visible to the group.
2. Connect two 24” Toobeez tubes into a straight line along the multi-holed equator of a sphere. This will serve as the 0º/180º line of the Toobeez protractor model. (*If enough Toobeez sets are not available, three models can be made per Toobeez set. The teacher model can be modified by using 36″ tubes, and student groups can construct models using either 24” or 16” tubes.)
3. Insert a 24” Toobeez tube into the center sphere along the multi-holed equator so that it is at a right angle with the tubes of the 0º/180º line. This will serve as the 90º line of the Toobeez protractor model.
4. Insert two additional 24” Toobeez, one on either side of the 90º line, so that both are midway between the 90º and 0º/180º line.
5. Teachers should hold their protractor model up to the center of the chart paper and have students do the same in their groups.
6. Using a red marker, color the chart paper to the right of the 90º tube.Write the word “acute” (<90º) above this area.
7. Using a green marker, write the word “right” above the 90º tube.
8. Using a blue marker, color the chart paper to the left of the 90º tube. Write the word “obtuse” (>90º) above this area.
Here are available Training Options!
1. Divide the students into groups.
2. Read aloud the following Activity Challenge Box to the group.
Challenge: The group should be able to use a protractor to identify qualities of angles.
3. Teachers should begin with a mini-lesson on measuring angles and protractor use. Hint: Use the Toobeez protractor model as an educational prop in the mini-lesson.
4. Using the remaining Toobeez pieces, each group should build model of each type of angle and classify it.
5. At their desks, each student should draw three examples of obtuse and acute angles.
6. Using their protractors, students should measure their hand-drawn angles.
7. After the activity, circle up the group and ask them the following questions: “How is a protractor used to identify types of angles?”
8. Finally, move to the “Activity Discussion and Processing” section of the activity.
To close the lesson, end with a group discussion about what was learned during the activity. Circle up the group and work through the following questions. If possible, record the group’s responses on flip chart paper so all comments are displayed.
Here are some additional topics for class discussion:
1. A different view.
Insert eight 24” Toobeez tubes into a sphere along the multi-holed equator. Present this to students as the interior model of a circle. Challenge the class to deduce from the model how many degrees are in a complete circle.
2. Extension/Follow up.
At their desks, have students draw several examples of some geometric shapes (for example, triangle, square and rectangle). Then have the students measure and record the angular measurements of these shapes. Challenge the students to identify any observed mathematical rules from their findings (for example, all the angles in a triangle add up to 180º).