Science Activity
#5 - Shapes and Polyhedra
All experiments must be done in the presence of a parent or teacher.
 Ideas Key Words Materials Procedure Observations Summary Questions WWW Links

Ideas to be Developed
Through chemistry, a variety of three dimensional shapes and polyhedra can be found in nature. In order to be able to identify some of these different shapes students need to be able to identify the characteristics of each one.

Key Words
 cube - has three squares at each corner tetrahedron - has three equilateral triangles at each corner dodecahedron - has three regular pentagons at each corner octahedron - has four equilateral triangles at each corner icosahedron - has five equilateral triangles at each corner

Materials Required

Each student will need:

• 15 straws
• 60 small paper clips
• 30 thin rubber bands

Procedure
Straw structures:
http://www.georgehart.com/virtual-polyhedra/straw-tensegrity.html

Folding polyhedra:
Click for the paper models of the polyhedra. Cut, fold along all the lines, and use a glue stick to glue the tabs to form each of the following shapes. Click here to view how they fold into the 3-D shapes.
cube tetrahedron dodecahedron octahedron icosahedron
bucky ball

Observations
• students will identify the name of the shape they have built
• students will describe the characteristics of the shape they have built

Summary

Questions
Exercise: Get to know these polyhedra and the relationships between them by counting the number of faces, edges, and vertices found in each of these five models. Make a table with the fifteen answers and notice that only six different numbers appear in the fifteen slots.

Fill in this table:

 # faces # edges # vertices tetrahedron __________ __________ __________ cube __________ __________ __________ octahedron __________ __________ __________ dodecahedron __________ __________ __________ icosahedron __________ __________ __________