Assuming the solid likes are the design. So we see two parallelograms there.
Area of 1 parallelogram = base x height. Since we have a joint height, we will multiply the total height with the base (both have the same base length) to get the area of 1 design.
The product of two numbers is the result you get when you multiply them together. So 12 is the product of 3 and 4, 0 is the product of 4 and 5 and so on.
