angle models made of paper

1. Angle-a-trons
Anica Trickovic

2. I got inspiration for this class from a video on Khan academy called “Angle-a trons”
Link for this video:
https://www.khanacademy.org/math/recreational-math/vi-hart/spirals-fibonacci/v/angle-a-trons

3. What does the word “angle-a-trons” means?
• the suffix "-tron" denotes a complex scientific instrument
• angle models made of paper

4. Description of the lesson

5. Are there any angles on this piece of paper?

6. 90° angle 180° angle

7. What about this irregular piece of paper?

8. With one fold we can turn it into 180° angle-a-tron

9. 90° angle we can get
by folding a 180° angle-a-tron in half

10. 45° angle we can get
by folding a 90° angle-a-tron in half

11. 22,5° angle we can get
by folding a 45° angle-a-tron in half

12. and so on…

13. It’s not hard to fold the paper in thirds either

14. We can get an angle of 60°
by folding 180° on three equal parts

15. 60° angle-a-tron

16. By folding 60° angle-a-tron into half
we can get an angle of 30°

17. Then we get an angle of 15°
by folding 30° angle-a-tron in half

18. We can add them together…

19. We can put two angles of 60° together to get 120° angle-a-tron

20. We can get 135° by adding 90° and 45°

21. Together with students we make all angle models from
paper.
Students check the angles with their protractors after
they make the models.

22. Activities for students

23. Students are divided into four groups

24. Every student draws a picture, using just one ruler and
angle-a-trons which they made. If they have time, they
can colour the drawings. Students can help each other .

25. Group 1:
Use angle-a-tron of 90°

26. Group 2:
Use angle-a-trons of 90° and 45°

27. Group 3:
Use angle-a-tron of 60°

28. Group 4:
Use angle-a-tron of 120°

29. Every group chooses the best
drawing which will be displayed on
the classroom wall.

30. Summary

31. I remembered when I was a student that my teacher
showed us how to make angle-a-trons.
We usually don`t carry around a protractor, so this can
be useful to the students because they can make their
own angle models.
In the same time, students can see the size of the most
used angles 180°, 90°, 45°; ...,60°, 30°, 15°,...

32. I think the students will specially like the drawing activity
using rulers and angle-a-trons made of paper.