Science
Activity
#5  Shapes and Polyhedra


All
experiments must be done in the presence of a parent or teacher.



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/virtualpolyhedra/strawtensegrity.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 3D 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 
__________ 
__________ 
__________ 

WWW
Links 
1.
Puzzles
with polyhedra and numbers
At
this site one can print copies of polyhedron puzzles (for noncommercial
purposes only) and read several mathematical articles on the subject.
2.
http://www.georgehart.com/virtualpolyhedra/platonicinfo.html
3. http://www.georgehart.com/virtualpolyhedra/strawtensegrity.html
4.
Watch
the polyhedra fold and unfold
