The perimeter of the polygon is 28cm. The length of each side is 40mm. What is the name of the polygon?

This type of assignment is basic and most common in the subject of mathematics. In order to learn how to quickly and correctly solve them, you need to master or remember some mathematical rules. To solve this task, you need to remember the formula for the perimeter of a figure with the same sides. The perimeter of such a figure is equal to the sum of all its sides. Therefore, in order to find out the number of sides of such a figure, we need to divide the perimeter by the length of one side. We get:

40mm = 0.4cm

28: 0.4 = 70 (sides)

Therefore, this figure is called a seven-sided figure.

Answer: the seven-sided.