A square is 8 inches long each side a rectangle is 6 inches wide and 10 inches long wich shape has the greater perimeter? Explain

The word greater means GCD, you first do the god of 8 and 8 then do the gcd of 6 and 10 after that one should subtract. and when you do the gcd of the square you will get 8 and for the rectangle you will get 2. then it will be 8-2 which will be equal to 6