The diagram shows a large rectangle composed of nine identical smaller rectangles.
Both the length and breadth of each of these smaller rectangles are whole numbers of centimetres. Which of the following could be the area of the large rectangle?
a. 450 square centimetres
b. 1260 square centimetres
c. 1620 square centimetres
If you liked this problem, here is an NRICH task
which challenges you to use similar mathematical ideas.