This is very important because when you make the cube, you are practicing design and construction skills.

These skills can be used to help

you make more complicated

structures.

You will need these skills because we are now going to design and construct a more complicated structure: The

Although the structures may look different, they have one thing in common; they have four connecting flat triangular surfaces.

When you made the cube you discovered that you had six congruent flat surfaces. All squares have congruent surfaces.

To make the cubic decimeter tetrahedron I had to make four equilateral triangles.

I used 1cm graph paper, a ruler, glue stick, roller and boxboard to make the first equilateral triangle.

I used a pencil compass, pencil, ruler and boxboard to make the second equilateral triangle.

I used a beam compass, pencil, ruler and boxboard to make the third equilateral triangle.

I used a pencil, and the first equilateral triangle, carefully cut to the proper size, as a template to trace and construct the final equilateral triangle.

Let's make the first equilateral triangle using graph paper.