Wall length, perimeter = length +2x width.

Wall width, perimeter = width +2x length.

The difference between parallelogram and rectangle, diamond and square;

For parallelogram, the unique properties of rectangle are: all four corners are right angles; The two diagonals are equal and equally divided (the basis for judging that the median line on the hypotenuse of a right triangle is equal to half of the hypotenuse). The unique nature of diamonds: all four sides are equal; Two diagonal lines are perpendicular to each other, and each diagonal line bisects a set of diagonal lines. The sum of the unique properties of rectangle and rhombus is the unique properties of square for parallelogram.

Generally speaking, to prove that a quadrilateral is a rectangle or a diamond, we must first prove that a quadrilateral is a parallelogram, and then prove that a parallelogram is a rectangle or a diamond. When proving whether it is a square, we can start from two aspects. Like proving a rectangle or a diamond, we first prove that it is a parallelogram, then prove that it is a rectangle or a diamond, and finally prove that it is a square through known conditions or verification.