What you need:
- drinking straws
What to do:
- Split up into teams of at least two people.
- Give each team a packet of straws and marshmallows and a pair of scissors.
- Make a square out of straws cut to about 3/4 length and use the marshmallows as corner joiners. Now make another square.
- Make a cube using the two squares you have already made as the top and bottom of the cube. Use four more 3/4 length straws as the risers.
- Use some full length straws as cross braces across the middle of some of the faces of the cube.
- Now compete in some challenges:
- tallest tower (or pyramid)
- strongest tower
- widest span (eg bridging between two tables)
- tallest / strongest / widest with smallest number of straws or marshmallows
- build a dome
- most creative structure
- Eat any of the remaining building materials!
Buildings are often supported by girders that interlock to provide rigidity and strength with a minimum amount of material. The basic unit of these truss structures is usually a triangle. You can see these triangle structures on steel span bridges (eg Sydney Harbour Bridge).