The rectangle is divided into squares. Find the perimeter of the rectangle if the side of the filled square is 9 cm.

In order to find the perimeter of a rectangle, you need to know the width and length of the sides of the rectangle. P = (a + b) * 2, where P is the perimeter, a is the length, and b is the width. By the condition of the problem, it is specified that the rectangle is divided into squares. And also the condition is set that the side of the square is 9 cm.It is also known that all sides of the square are the same, which means that the width of the rectangle is also 9 cm.If the rectangle is divided into squares, and the side of the square is 9 cm, then the length of the rectangle is 9 * 2 = 18 cm.
P = (9 + 18) * 2 = 27 * 2 = 54 cm.
Answer: 54 cm.