- Straws ( got mine at a grocery store)
- Mini brads
- Paper punch (about 1/16" diameter)
- How to calculate a triangle if you know the angle and one of the length? If your students are high school, you can use trigonometry.
- Triangle is the strongest and more economical shape. Talk about angles in a triangle
- Constraints. My straw length is about 7". The longest straw should be no longer than the material.
If you have a middle schooler, you can relate this with trigonometry. For this activity, I have a "cheat sheet" from youtube. https://www.youtube.com/watch?v=Z1ZLoQc0ay0
If the outside of pentagon = N, the R for the pentagon is Nx0.8696 or Nx1.0224 for hexagon.
If the longest straw is 5.5" = N, the r for pentagon is a 5.5"x0.8686 = 4.78"
Cut straws to 2 sizes:
Green: 5.5" ( about 35 pieces)
Blue: 4.75" ( about 30 pieces )
Hole punch both ends and connects it with brads.
Then connect horizontal lines using green straws. Then add the vertical blue straws as pictured.
Connect the last brad.
You made a model from straw. Want to be more creative? Instead of straw, try using rolled newspaper... See how big it can get.