Raven tapes four straws into a square.
She gives one corner a gentle push. The square squishes flat!
Rocket tapes three straws into a triangle and pushes it too.
"It stays a triangle!" Rocket says.
Nova glows. "Great discovery! What do you notice about the corners?"
Push the corner of a square frame.
It leans over into a slanted shape.
Push the corner of a triangle frame.
It keeps its shape, unless a side breaks or bends.
Engineers often use triangles to make bridges strong.
You can add a straw across a square.
That makes two triangles inside it!
| Idea | True or false? |
|---|---|
| A square frame can squish into a slanted shape. | ? |
| A triangle frame keeps its shape when pushed. | ? |
| Engineers never use triangles. | ? |
Triangle shapes are all around us.
Engineers use them in bridges.
You might spot them in a roof or a step stool too.
You found a strong shape!
Tomorrow, we build our ball tower.