In the above figure, the identical squares 
, 
, 
appear different in width and height, because subdividing
a space makes it appear larger.
A different orientation can also produce an illusion of enlargement. As illustrated above, a square whose diagonals are placed horizontally and vertically seems larger when put beside an identical square with horizontal and vertical sides.
Vertical lines appear longer than horizontal ones. For this reason, the square 
in the illustration above seems to be
too tall, while the rectangle 
appears to be a correctly drawn square.
