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How many triangles can you make using sticks that are 3cm, 4cm and 5cm long?
Each side can only use one stick but a triangle can use more than one stick of the same length.
You could use the interactivity below to investigate the problem and try making some triangles.
You need to choose three sticks by clicking on the red, green or blue buttons.
You can then rotate each stick (turn it round) by clicking and dragging on its end.
If you click and drag near the middle of a stick, you can move it.