How to Make a Pyramid Project Out of Foam Board

Draw an equilateral (all sides the same length) triangle on a piece of paper. Each side should be 10 inches long. Use a protractor to make sure all the angles are 60 degrees—equilateral triangles always have angles of 60 degrees. Cut out the triangle template.

Place the template on the foam board, and trace around the outline. Do this four times, positioning the template along the side of the adjacent triangle, to save space.

Cut out the triangles, cutting with a utility knife at a 22-degree angle, with the angle pointing into the triangle you are cutting. This way, the sides will match up in a proper joint when you assemble your pyramid.

Assemble the triangles into a pyramid shape, the points all meeting at the top, and the angled edges connecting. Run a line of glue between each joint, pressing the sides of the triangles together firmly to set the pyramid shape in place.

Paint the pyramid in a golden-sandy color, painting in details of bricks with a darker orange or sandy brown. Let dry.

Cut a 30-inch square of foam board, and four 30- by 3-inch lengths of foam board. Glue the 30- by 3-inch lengths around the edges of the square, at right angles, to make a walled base for your project. Let dry.

Pour sand into the walled base, creating dips and peaks like dunes. Press the pyramid into the sand, wriggling it down in the sand so that it is stable—because the pyramid has no base for this project, it will sit firmly in the sand as the sand surrounds the inside and outside walls of the pyramid.