Vincent and Tara are making triangles with the class construction set. They have a pile of strips of different lengths.
There are plenty of strips of each colour.
There are yellow strips with 3 holes, black strips with 4 holes, red strips with 5 holes, green strips with 6 holes, orange strips with 8 holes and blue strips with 10 holes.
Vincent makes a triangle with a blue strip, an orange strip and a red strip.
Tara makes a triangle with two green strips and one red strip and another triangle with 3 black strips.
How many more different triangles can they make with these strips?
Start younger and less able children with a few different strips, rods or straws from a class construction set.
The rods can be made from strips of card cut to length - but remember to leave a bit extra on the ends so that they can joined with push-through brass paper fasteners. There is no need to use all the lengths at the beginning - start with four or so and add others as needed.
The children should be led to discover and express how rigid triangles are and which combinations cannot be made, and why.
The most able could find a way of showing that they have all the possible triangles which meet the criteria.
