Wheel of Theodorus – Project

During internship in my math 8 class my students created these awesome Wheel of Theodorus projects and I just had to share them with you!

But first a little background information… (I promise it will be quick)

Theodorus  was a Greek mathematician of the 5th century BC. During my lesson we didn’t spend anytime researching about his life since my project differed than what his sole theorem was I maybe next time will spend some time researching. You can check out his sole theorem here (I’m not going to go into detail).

You can check out my instructions here,

But if you don’t want to here is a brief explanation.

Step 1: Put a dot in the middle of a white piece of paper.

Step 2: Draw a right triangle with legs 2cm (or use whatever length you want) Hint: Make sure the right angle isn’t attached to the dot. See picture.


Step 3: To create the second triangle you will use the hypotenuse from the first triangle, and draw another leg. Make sure the leg you draw will always be the same as the units you used for the first triangle (mine will always be 2)

Step 4: Connect the new leg to the middle.


Step 5: Repeat steps 3 and 4 until you have as many triangles as you want. I made my students create 20 triangles. As you can see on my finished circle I haven’t labeled any sides or hypotenuses and it’s not very colourful.20160121_143802_resized

My students had the chance to decorate theirs and solve for the missing sides. Students showed their work for the first 10 and if they could see the pattern they didn’t have to do the other. Also if the number was irrational they left it as a square root and if it was rational they solved the question. Check them out:

Some are just colourful:

20151118_114058_resized 20151118_114252_resized


Others have designs




Fruit Horn








Gary the Snail

What do you think of their work? Honestly I was so surprised and proud of the quality I got from them. Are you interested in this lesson? Let me know and I’ll give you more information on it. Anyone else do sweet projects with their students in math?