There is another way to construct a regular dodecahedron. To make this, you will need...
12 sheets of A4 paper
...and that's it! Well, you've got to make it, but...
Step 1: Take your sheet of A4 and fold it in half longways. Now unfold it. Now fold it in half the other way. You have just found the centre of your piece of A4:
1 _____________ 4
| : |
| : |
|......:......|
| : |
|______:______|
2 3
Step 2: Fold corner 1 into the middle, so that the corner just meets the middle. Do the same for the other corners, in order. You should now have a hexagon, with two short sides and two flaps (labled x and y):
_____________
/\ : /\
/ \ : / \
/ \ : / \
/ \ : / y \
/ \ : / \
/__,-¯¯-.__\:/__ __\
\ /:\ '-__-' /
\ x / : \ /
\ / : \ /
\ / : \ /
\ / : \ /
\/_____:_____\/
Step 3: Fold along the dotted line, and hook the two flaps together so that the whole thing stays like that. You should now have:
______ 1
/ |
/ |
3/ |
/ |
/ |
/...........|
\ |
\ |
\ |
4\ |
\ |
\______|
2
Step 4: Now you need to fold the corners 1 and 2 to touch the centre line. The fold meets the edges at points 3 and 4. To get the folds in the right place, make sure you have one straight line through 3-1-4-2. You should now be left with a pentagon:
_
/|¯'-,_
/ | ¯/|
/ | _-_ / |
/...|/ Y..|
\ | \ |
\ | \|
\ | _,-'
\|,-'¯
Step 5: Repeat steps 1-4 with your other 11 pieces of A4, to get 12 pentagons. Notice that each pentagon has one blank side, two sides with flaps on, and two sides with slits in...
Step 6: Begin slotting the pentagons together, flap into slit. Make sure that every blank edge is next to another blank edge. Get frustrated trying to put the last piece in.
And now you have a wonderful football/dodecahedron. But don't kick it!