### Video Transcript

Calculate the perimeter of a square whose side length is four and a half metres.

Remember that the perimeter of the square, in fact the perimeter of any shape, is the distance all the way around it. So in the case of a square, it’s the total of all four sides. We’re given the length of one of these sides in the question. We’re told to calculate the perimeter of the square whose side length is four and a half metres. We know that, with a square, all the side lengths are the same. So the perimeter of a shape is worth four lots of four and a half.

To help us multiply by four quickly, we can partition four and a half into four and one-half. Four times four equals 16. And four lots of a half equals two. And if we add the two together, we get 18. All the side lengths of the square are the same length. So to find the perimeter of a square whose side length was four and a half metres, all we had to do was to multiply four and a half by four. The perimeter of the square of the distance all the way around is 18 metres.