# Building A Pyramid

A hands-on exercise: from net to geometric solid.

#### by Eldred Marshall

CA Mathematics Standards Alignment
Measurement and Geometry 1.3
Mathematical Reasoning 1.0
Measurement and Geometry 1.2
Mathematical Reasoning 1.0
Algebra I 25.0
Students construct a scale model of the Great Pyramid at Giza. In the extension questions students are asked to use given formulas to calculate the surface area and volume of their model.

#### MATERIALS:

1. Four 8 1/2" X 11" sheets of paper
2. Four scissors
3. Four rulers
4. Four black pencils
5. Four red pencils
6. Four blue pencils
7. Tape

#### DIRECTIONS:

Note: Each student will make a pyramid individually; however, students should help each other as they are completing the task.

1. Following Diagram 1, fold one corner of the paper to the opposite side. Cut off the extra rectangle. The result is an 8 1/2" square sheet of paper.

2. Fold the paper in half and in half again. Open the paper out and mark the midpoint on each side. Draw a line connecting opposite center points.

3. Measure 3 1/4 inches out from the center on each of the four lines. Draw a red line from each corner of the paper to each point you just marked. Cut along these red lines to see what to throw away.

4. Draw blue lines as shown below.

5. Neatly print your name at the base of one of the sides of the pyramid (before folding and taping).
6. Fold along the lines. Tape the edges together.

7. Congratulations! You now have a pyramid that is a scale model of the Great Pyramid at Giza.

#### PRODUCT:

One pyramid per student.

#### BONUS:

Calculate the surface area for your pyramid using the formula: SA = b^2 + 2bs, where b is one of the sides of the base and s is the slant height (the distance from the base to the vertex of one of the triangular faces).

SA = _______________________ in.^2 (square inches)

Calculate the volume of your pyramid using the formula: V=b^2h/3, where b is one of the sides of the base and h is the height.

V = _______________________ in.^3 (cubic inches)

#### CLEAN-UP:

All materials listed should be neatly placed in the basket.

versión español