Much of what we see in the world, and in representations thereof, is not actually the shape that we perceive it to be. For example: when you look at a door you perceive a rectangle — assuming you are not a Hobbit — but what you are seeing is actually trapezoidal in nature, or some other geometric distortion of a rectangle, unless you are somehow able to look at the entire door from a point normal to its surface.
Most people are familiar with the vanishing point in pictures (paintings as well as photographs). We perceive lines converging at the same point to be parallel, but they obviously are not, lines that converge cannot be parallel… unless they converge at infinity.
The interesting thing to me, is that these lines, in reality, are parallel. So we see parallel lines as converging lines and perceive them as parallel. I guess if you get to the right answer in the end it doesn’t matter if your method is flawed?