How can a person build a pyramid out of cardboard?

To build a pyramid out of cardboard, use four cardboard triangles and one cardboard square. The pieces can then be taped or glued together.

The following example uses a 4-inch base, which is close to scale but not exact. A pyramid's exact dimensions are determined by calculating the apothem and using the Pythagorean theorem.

Step 1: Cut the base

Cut a 4-inch square piece of cardboard.

Step 2: Cut the triangles

The base of the triangles must be the exact same as the sides of the square and about 3 inches tall. However, equilateral triangles will work.

Step 3: Tape the pieces

Tape the triangular pieces together on the longer sides, and then tape the base to the triangular part and decorate if desired.