angle a-trons.pptx
TRANSCRIPT
Angle-a-tronsAnica Trickovic
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
What does the word “angle-a-trons” means?
•the suffix "-tron" denotes a complex scientific instrument
• angle models made of paper
Description of the lesson
Are there any angles on this piece of paper?
90° angle 180° angle
What about this irregular piece of paper?
With one fold we can turn it into 180° angle-a-tron
90° angle we can get
by folding a 180° angle-a-tron in half
45° angle we can get by folding a 90° angle-a-tron in half
22,5° angle we can get by folding a 45° angle-a-tron in half
and so on…
It’s not hard to fold the paper in thirds either
We can get an angle of 60° by folding 180° on three equal parts
60° angle-a-tron
By folding 60° angle-a-tron into half
we can get an angle of 30°
Then we get an angle of 15° by folding 30° angle-a-tron in half
We can add them together…
We can put two angles of 60° together to get 120° angle-a-tron
We can get 135° by adding 90° and 45°
Together with students we make all angle models from paper.Students check the angles with their protractors after they make the models.
Activities for students
Students are divided into four groups
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 .
Group 1:
Use angle-a-tron of 90°
Group 2:
Use angle-a-trons of 90° and 45°
Group 3:
Use angle-a-tron of 60°
Group 4:
Use angle-a-tron of 120°
Every group chooses the best drawing which will be displayed on the classroom wall.
Summary
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°,...
I think the students will specially like the drawing activity using rulers and angle-a-trons made of paper.