Question

How do you write the area of the rectangle as a product and as a sum?

Answer 1

Well, I can't see the rectangle you're working with,
but as far as I know, the area of a rectangle can ONLY
be written as a product.

The area of EVERY rectangle is

           (its length) multiplied by (its width) .

I can't think of a way to write that as a sum.

Answer 2

Product: 
L2 + W2

Sum: 
L + L + W + W