Which Building Shape Is Strongest?

1. Use your kit's manual to build a basic square-sided structure. Observe how easily its frame changes shape when gently pushed.
2. Place a lightweight platform on top, if it can be supported securely.
3. Add identical weights one at a time, recording how many the structure supports before visibly deforming. Stop before it collapses.
4. Record your results and repeat the test three times, rebuilding the same structure each time.
5. Build a second structure with the same basic dimensions, adding diagonal braces to create triangles.
6. Repeat the weight test using the same platform, weights, and placement.
7. Compare the results. Which structure supported more weight without deforming?
8. Calculate the average weight supported by each design.

What you change: Whether the structure has diagonal triangular braces.

What you measure: The number of identical weights the structure supports before visibly deforming.

What stays the same: The structure's basic dimensions, platform, type of weights, weight placement, and testing method.

Science fair tip: Count the weights supported during each test and create a bar graph comparing the average results.

Engineers use triangles to make buildings, bridges, and towers more stable.

A square frame can change shape when force is applied to its corners. Adding a diagonal brace creates triangles, which resist changing shape unless their sides bend or stretch.

This technique is called triangulation. It helps structures resist forces such as wind and movement.

Think about it: Did adding braces make your structure stronger? Could you design a structure that uses fewer materials but still supports the same amount of weight?