problem
Four triangles puzzle
Age
5 to 11
Challenge level
Cut four triangles from a square as shown in the picture. How many different shapes can you make by fitting the four triangles back together?
problem
Inside triangles
Age
5 to 7
Challenge level
How many different triangles can you draw which each have one dot in the middle?
problem
Nine-pin triangles
Age
7 to 11
Challenge level
How many different triangles can you make on a circular pegboard that has nine pegs?