We've included questions (in italics in the description above) that you can ask the group to get them involved.
You can use a large loop of string (one about 6m long works welll) to explore how the area of a room (enclosed by a fixed length of wall) changes as you alter the shape. Ask for two volunteers and ask them to pull the loop taut., giving you a room you with just two corners – it’s not a very useful room as it encloses no room at all. The room becomes much more useful if you add a third corner, creating a triangular room which now encloses some space. Continue asking for new volunteers to add a corner to the room and note that the area enclosed continues to increase.
It is also useful to have a wok (or similarly curved dish) and a bag full of marbles. If you empty the marbles into the dish they will settle into a hexagonal pattern, demonstrating that making the honeycomb arrangement uses the least energy.