Calculate the perimeter of the rectangle if its length is 2 dm and the shilin is 8 cm less than the length.

At first glance, it may seem that the width in this problem is negative, since 2 is greater than 8. However, the length is given to us in decimetres, let’s translate it into centimeters:
2 dm = 2 * 10 cm = 20 cm.
The width of the rectangle is 8 centimeters less, which means that the width is:
20 – 8 = 12 cm.
The area of a rectangle is known to be equal to the product of its length and width. Let’s find it:
20 * 12 = 240.
Answer: 240.