Calculate the perimeter of a rectangle 2 dm length 30 cm width.

In order to make the correct calculation of the perimeter in the future, we will bring the data specified in the conditions of this task to a single unit of measurement – centimeters, since we know that one hundred and ten centimeters is the same as one decimeter:
2 * 10 = 20.
Let us calculate how many centimeters the perimeter of the specified figure will equal, if we know, according to the data from the conditions of this task, that its dimensions are 20 centimeters by 30 centimeters:
(20 + 30) * 2 = 100.
Answer: The perimeter is 100 cm.