IN THIS LESSON

Engineers design bridges and buildings that stay strong and steady.

Today you’ll test shapes to see which is more stable — a square or a triangle. You’ll discover why engineers use triangles in tall towers, bridges, and roofs.

Step-by-Step Guidance

  1. Build Two Frames

    • Make one square frame and one triangle frame using straws, sticks, or paper strips taped together.

    • Try to keep the sizes similar.

  2. Test Stability

    • Gently push on the side of each frame.

    • Watch what happens.

    • Does the square wobble? Does the triangle stay stiff?

  3. Compare Results

    • Which frame was stronger?

    • Why do you think the triangle resisted better?

  4. Record & Reflect

    • Draw both frames.

    • Fill in the reflection: The triangle was stronger because __.

Download PDF

  • Key Concept

    Triangles are the most stable shape in engineering. Unlike squares, they don’t bend or collapse under pressure because their sides lock together. That’s why engineers use triangles (trusses) to make bridges, towers, and roofs safe and strong.

    Extension Ideas

    • Math Connection: Count how many triangles you see in a bridge or playground structure.

    • Science Connection: Add a diagonal “brace” to the square — what happens now?

    • Literacy Connection: Write a mini “engineer’s report” about which shape won the test.

Early Engineers: Triangle Truss Tester

Predict → Match → Quiz. Super simple stability lesson.

Module

1) Make a Prediction

Which frame stays steadier with the same push?

2) Match the Ideas

Tap one from the left and its match on the right. Get all 4 to continue.

Matches: 0/4

3) Was the Prediction Correct?

...

Quick Quiz

Choose the best answer.

1) Which frame was more stable?
2) Triangles are strong because they ______.
3) A fair test uses the ______ push each time.
4) A brace adds ______ to a frame.
5) Compression is a ______ force.
Score: 0/5

Print this page as PDF for proof of completion.