It is known that the perimeter of a large rectangle is 30 cm, and the shadow part is a rectangle. How about the length and width of a large square?

It is known that the perimeter of a large rectangle is 30 cm, and the shadow part is a rectangle. How about the length and width of a large square?

The length and width of a square are equal (30-3 * 2) / 4 = 6

A rectangle is made up of seven rectangles of the same size. The perimeter of a large rectangle is 34 cm

Let the length and width be x cm and Y cm
（x+7y)*2=34
x+7y=17
When integer solution x = 3, y = 2
When x = 10, y = 1
The length and width of a rectangle are 3cm, 2cm or 10cm, 1cm respectively

As shown in the figure, a rectangle is made up of eight identical small rectangles. The perimeter of the large rectangle is 40 cm. Find the length and width of the small rectangle (use equation solution)