Below is an optical illusion that seems simple enough.
Which distance is longer? Is the distance between the tips of the first two opposing triangles pointing away from each other (A-B) on the left longer? Or is the distance between the points of the second two triangles facing each other (B-C) on the right longer?
You don't need me to tell you that it appears that the tips of the second two triangles (B-C) are further apart. It also seems that the tips of the first two triangles (A-B) are closer together.
If it was that easy though this image wouldn't be here would it? The truth is that the distance between the two sets (A-B) and (B-C) are exactly the same.
Go ahead get out your fine point marker and a ruler and see for your self, you know you want to. BTW don't use a Sharpie.