Video Transcript
The perimeter of a square piece of paper is one and one-third meter. What is the length of the piece of paper?
Here’s our square paper. And it has a side length of 𝑥 meters. We don’t know how many meters. We do know that the perimeter is the distance around a figure. And the distance around the square is a side plus side plus side plus side. In other words, the perimeter of a square is four times the side length. Our perimeter is one and one-third meter. So one and one-third is equal to four 𝑥, four times the side length.
It’s not very easy to work with mixed numbers here. So it’s better for you write it as an improper fraction. One and one-third is the same thing as three over three plus one-third. Three plus one is four. One and one-third is the same thing as four-thirds. Four-thirds equals four 𝑥.
To get 𝑥 by itself, we divide the right side by four. Remember that dividing by four is the same thing as multiplying by one-fourth. So the fours on the left cancel out. And the fours on the right cancel out. One-third equals 𝑥.
And that means each side of the square is one-third meter.
