Volume Postal requirements specify that parcels must have length plus girth of at most 84 inches. Consider the problem offinding the dimensions of the square-ended rectangular package of greatest volume that is mailable.(a) Draw a square-ended rectangular box Label each edge of the square end with the letter xand label the remainingdimension of the box with the letter h.(b) Express the length plus the girth in terms of x and h.(:1 Determine the objective and constraint equations.(d) Express the quantity to be maximized as a function of x(e) Find the optimal values of x and h.