Bendy Straws and Quadrilaterals


What shapes* can you make with the bendy straws?

* Do the ends have to connect? We can either require that the ends connect, or not. 

You can try to make a triangle.


But can you always make a triangle out of the two straws? What requirements are there? Did you try extending the straw out all the way? Did you try scrunching it in?


I see a shape there, but I notice that the ends don’t connect perfectly. Can you make them connect perfectly?  IMG_2967


What categories of shapes are we able to make if the ends have to connect perfectly? (And we can use a bit of tape to make sure that the ends are sticking together.)

Are there more categories? How do we know?

What’s special about these shapes? What happens if you flip one of these shapes onto its back side? What changes? Why?

I think that this might be a nice mini-investigation that could motivate some proofy concerns.


One thought on “Bendy Straws and Quadrilaterals

  1. Love it! I’ve done stuff like this with linguine broken into pieces, but straws are just inherently more fun for the 9-10th grade set. Plus, limiting the realm of possibilities somewhat might be useful. Maybe I will try it with both materials on hand.

    Suggestion: Get some chenille stems (aka pipe cleaners) to chop up and stick in the ends of two adjacent straw openings as connectors so that they don’t roll away from each other.

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