Video Transcript
Calculate the perimeter of the square 𝐴𝐵𝐶𝐷.
The perimeter is the distance around a two-dimensional shape. We find it by adding all the side lengths together. What do we know about a square? In a square, all side lengths are equal. To find the perimeter of a square, we multiply four times one of the side lengths. That is the same thing as saying the perimeter equals side plus side plus side plus side. So instead of doing repeated addition four times, we can multiply our side length by four.
In this case, the side length is 37 centimeters and we need to multiply that by four. Starting all the way on the right, we say four times seven equals 28. We write our eight down and carry our two. Moving on to the tens place, we say four times three equals 12 plus the two that we carried over equals 14. So we bring down that 14.
37 times four equals 148. But make sure we don’t forget the units. They’re a very important part of calculating the perimeter. We can bring those units down to tell us that the perimeter of this square is 148 centimeters.
