Can you solve them all?

This will make your brain work a bit.

I'll help you out with the interface:

Click Figuur1 on the left side.
What your end result should look like will come up in the upper left; at the bottom of that screen is the number of blocks you need to use.

To add blocks, just left click. To take a block away, just select the "break down" bullet, and click the block you want to remove.

There are no physics, so blocks CAN float.

You'll get a "green" bullet next to "Figure#" when the image is right but you have too many blocked used. Yellow means you nailed it.

Took me ~15 minutes to get them all yellow. Honestly, figure 1 is one of the hardest to get yellow. Don't worry about the minimum blocks at first - just build them, then start taking blocks away.

http://mathsnet.net/geometry/solid/houses.html

Update: #1 and #9 are easily the hardest. Funny enough, after 10 minutes this time around I couldn't solve #9. Had one extra block somewhere.