I don't know if I can explain this in words but here goes:
The red piece uses up 8 blocks in length, and the teal piece uses up 5. The entire length of the combined triangle is 13 blocks, hence 8+5. All that's done is the the flipping of the orange block first to create the necessary space to switch the green & red blocks. The entire length still remains red + green (13), but the orange piece had to be slid down to accomodate the red one on top.
After reading what I wrote, it sounds like bullshit but damn it, I can see it.
The top image dips and the bottom image bows. Both of the angled pieces have lines drawn from one corner to another, so they actually both use the same surface area. The hole comes from the misperception that the angle is the same on both images.
Comment