Here's a little mind-boggler for you... (Disclaimer: I did not make this, and I don't know who did. It's just something I picked up somewhere.)

Cut out the following pieces (if you don't want to cut the monitor, sketch it out on squared paper first) and put them in the following configuration. (Sorry that the scale isn't right in this picture, it's the best I could do in ASCII...)

           /|\              ^
          / | \             |
         /  |  \            |
        /   |   \           |
       /    |11  \          
      /     |     \         15
     /      |      \        
    /___8___|___8___\       |
   /| 5  |          |\      |
  / |    |__6__     | \     |
 / 4|          |2   |4 \    |
/___|__________|____|___\   v
  3     11        5   3    

<---------- 22 --------->

Now, rearrange the pieces, so the triangle looks like this:

           /|\              ^
          / | \             |
         /  |4 \            |
        /_3_|_3_\           |
       /| 4  |  |\          
      / |    |  | \         15
     /  |   5|6 |  \        
    /   |   _|  |   \       |
   /  11|  |_|  |11  \      |
  /     | 6|    |     \     |
 /      |  |5   |      \    |
/___8___|__|____|___8___\   v
          2  4     

<---------- 22 --------->
So, my question is: How did you manage to get a hole in the middle, when you are using the same pieces to make the same triangle?

When you have solved it, or just totally give up, you can find the solution here.

Oh, one more thing. Please don't post any suggestions or hints on this node, as this may ruin the challenge for others. You can /msg me for comments or discussion, or post a writeup here.