Port Placement

Does it matter where you place the port on a box?  I just built a box for 2 12 MA Audio 1200XL in a 2 cubic foot dual chamber box.  I have the ports on the top of the box does it really matter.  Also I know to convert a round port into a square port you take half the round port and times it by X and then times it by 3.14.  Now I did that and came up with 12.56 square inches.  I don't under stand what that means.  I know the port is going to stay 11in deep but how wide do I make it and how long and if you know the answer how do you come up with the width and length so I don't have to bother you people with these retard questions.

The displacement of the port must remain the same. Thus if the area a circular port is  pieR^2 = x then to convert to a rectangular port you need to find two numbers, a and b that when multiplied = x. The port length stays the same.

If your calculation is 12.56" in surface area displacement, then to calculate a rectangular port we need to get pretty close to this.

2.0" * 6.28" = 12.56"

1.5 * 8.37 = 12.56

2.5 * 5.024 = 12.56