The perimeter of a rectangle is twice the length plus twice the width. The area of a rectangle is the product of its length and width. Suppose we let l represent the length and w represent the width of a rectangle.

a) Write an algebraic expression that represents the perimeter.

b) Write an algebraic expression that represents the area.

c) Calculate the perimeter of a rectangle 12 inches long and 20 inches wide.

d) Calculate the area of the rectangle described in Part C.