How is a perimeter used in our life?

Answer 1

Suppose you are going to build a fence around a rectangular garden or other plot of land.

How much fence material do you need to buy? Yes, the perimeter of the rectangle!

Suppose you need to put down molding around a room?

How much "1/4 round" do you need to buy?

Yes, the perimeter of the room, less and allowance for doorways.