for what values of x is the area of the rectangle greater than the perimeter?

If you are talking about a square:

     When is the area of a square greater than the perimeter of the square?

If a length of a sides is  x,  then the area is  x²  and the perimeter is  4x.

      x²  >  4x

      x² - 4x  > 0

     x(x - 4) > 0

Soling this for positive values of  x:

    x > 0   and   x - 4 > 0

    x > 0   and    x > 4

which is only true when  x > 4.