This is a math paradox that actually exists. The paradox is that though the space taken up by each individual figures is the same, the piece as a whole in different arrangements takes up less space. It is inconsistent with itself, and so it is a paradox.
This is a paradox because of the premise that Pinnochio's nose grows when he lies. His nose would only grow if the statement wasn't true, so it would be made true if it had been a lie at the beginning. This is a paradox because it presents an invalid, unsolvable argument that is problematic because of itself.
This paradox shows a painting of a wooden box, however the structure is an impossible one. This makes it a paradox. because since the structure is impossible, yet portrayed in the painting, its very portrayal goes against common sense. The box would be impossible to represent in real life because of its physical qualities.
