Final answer:
To find the area of a rectangle, multiply the length of one side by the length of the other side. However, without knowing the lengths of the sides, we cannot determine the area of the piece of wood.
Step-by-step explanation:
To find the area of a rectangle, we multiply the length of one side by the length of the other side. In this case, since John has a piece of wood that is in the shape of a rectangle, we need to know the lengths of the sides of the wood to find its area. The question does not provide this information, so we cannot determine the area of the piece of wood.