1. Attach a rectangle with a length of 20 cm. The circumference of this rectangle is () cm. If its length is 7 cm, its width is () cm.

2. Make a square with a 24-meter-long rope. The circumference of this square is () meters and the side length is () meters.

The side length of a square is 3cm, and the circumference is () cm.

4. Divide a rectangle with a length of 10 cm and a width of 5 cm into two squares on average, and the circumference of each square is () cm.

5. Put two squares with a side length of 3 cm into a rectangle, and the circumference of this rectangle is () cm.

6. The length of the rectangle is increased by 5 cm, the width is increased by 2 cm, and the circumference is increased by () cm.

7. The circumference of a square increases by12cm, and the side length increases by () cm.

8. When the side length of a square increases by 2 cm, the circumference increases by () cm.

9. The length of the rectangle is increased by 3cm, the width is increased by 1 cm, and the circumference is increased by () cm.

10, the length of the rectangle is 16 cm, and the length is twice as wide, so the circumference of the rectangle is () cm.

1 1, three squares with sides of 4 decimeters form a rectangle with a circumference of () decimeters.

12. The side length of the square is increased by 3 times, and the perimeter is increased by () times.