The width of the rectangle is 9dm and the length is 2dm longer. Find the area of a square with the same perimeter as the given rectangle.

1) We find out how long a given rectangle has if it is known that its width is 2 dm less and is equal to 9 dm.
9 + 2 = 11 dm.
2) Find out what perimeter a given rectangle has, if we learned that its length is 11 dm, and its width is 9 dm.
(9 + 11) * 2 = 40 dm.
3) Find out how long the side of a square with a perimeter of 40 dm is, if we know that the square has 4 sides and they are all equal.
40/4 = 10 dm.
4) Let’s find out what is the area of a square with a side of 10 dm.
10 * 10 = 100 dm².
Answer: the area of the square was 100 dm².