Box 5 is a triangular box which contains 8 blue triangles:
2 small equilateral triangles.
1 small obtuse angle scalene triangle.
2 large right angle isosceles triangles.
1 small right angle scalene triangle.
2 medium right angle scalene triangles.
To give the child the opportunity to experiment with various geometric shapes.
To show that all plane, flat, rectilinear figures are composed of triangles.
To indirectly prepare the child for later work in Maths and Geometry.
4 to 4.5 years approx.