What makes a structure stable?
A stable structure does not fall over easily. Buildings, towers and furniture need to be stable so they are safe to use. Three things help a structure stay stable.
Three ways to be stable
- Low centre of gravity — the weight is low and near the ground, so it is harder to tip over.
- Wide base — a broad bottom spreads the weight and gives more support.
- Strong shapes — shapes like the triangle are very strong and hold their shape well.
Key idea
A structure is more stable when it has a low centre of gravity, a wide base, and uses strong shapes such as triangles.
Examples around us
A racing car is low and wide, so it does not tip over on fast corners. A tall lamp has a heavy, wide base to stop it falling. Bridges and towers use triangle shapes because triangles do not bend or change shape easily.
Remember
- Low + wide = more stable.
- Tall + narrow = easy to topple.
- Triangles are the strongest shape.