Well, you have to fold the A shape so it is equal in size to a Z shape. You then supply vitamin D to this shape, and escort it to the console which plays tetris music by the sandy beaches in that one place. Afterwards, you lie, and say you only folded it, and it is the original A shape in squares, though it is a DZ shape after preforming the ancient ritual of hats. Got it?

The whole point of A2, A3, etc is that the ratio of sides is the square root of 2. That way exactly two A3's can be combined to form A2, or one A3 can be folded in halves of size A4. Since the square root of two is irrational, it will never divide evenly into squares. You can get approximate squares by folding it into a 3x2 grid (or 7x5 or 17x12 or 41x29, etc.)