Structure from triangles

Use Q tips with sticky ends, or marshmallows and toothpicks, to assemble a structure that is self supporting, such as the start of a bridge. The use of triangles in the structure will be critical to it being able to support itself.
Science content
Physics: Motion and Forces, Newton’s Laws, Gravity (K, 2, 6)
Lessons activity is in

sticky Q-tips method:

  • Q tips
  • rubber cement
  • wide popsicle sticks
  • baggies for the kits
  • masking tape

marshmallows and toothpicks method:

  • mini marshmallows
  • toothpicks

Before the lesson if using sticky Q-tips:
Dip the cotton tips of the Q tips in rubber cement, then leave to dry (turning frequently to start if glue drips downwards).
Paint rubber cement on the wide popsicle stick.
Package in baggies 30 Q tips and one wide popsicle stick per group.

For either method:
Ask students to make a structure that is made up of triangles. The structure could be high or wide.
If part of a bridges lesson, ask students to make the start of a bridge, with Q-tips building up from the popsicle stick and curving up and over. The challenge is to build a structure that is self supporting, as real bridge structures are (they do not hang on themselves, but are solid at every stage).
Tell students, based on previous discussions, or when they need assistance, that triangles are strong shapes that will support themselves, and so the should include many triangles in their structure.

Grades taught
Gr K
Gr 4
Gr 5
Gr 6