2. Filter paper parts of a circle: fold to find…
2 diagonals -> center
a cord
radii
a semicircle
an arc smaller than a semicircle
5-minute hands-on activity

3. Polyhedron Circle Exploration
Find the center without forming diagonals.
Fold a point to the center…
Fold a vertex to the center…
Create polyhedra…
Compare areas of figures as you go.
20-30-minute hands-on activity
I like to use a jumbo circle for the demo.

4. A Dodecahedron Construction
Uses 12 regular pentagons

5. Cut out 12 template
pieces and attach
with glue or staples.

6. attach a piece of thread to one protruding piece.
If you want to hang
your dodecahedron,
attach a piece of thread
to one protruding piece.

7. Questions:
How many pentagons
meet at each vertex?
How many pentagonal
faces are there?
How many vertices
are there?
How many edges are
there?

8. Dodecahedron Hints:
 You may find it easiest to check your alignment by watching the inside of the figure as you glue.
 You may wish to assemble one half of the dodecahedron (6 faces) first, then the other half, and then connect the two together.
 Too much or too little glue won’t hold.
You’ll need to use trial-and-error to
find the right amount. Perhaps a
toothpick or paper “spatula” would
be helpful.