### Video Transcript

Given that the area of each square
on the chessboard is 21 centimetres squared, find the length of the chessboard’s
sides.

So if the area of each square is
21, centimetres squared to be exact, then each side length will be the square root
of 21 because the area of a square is just equal to the side length squared. So the side length times the side
length. So if we know the area is 21, then
we set 𝑆 squared equal to 21. We square root both sides and find
that the side length is equal to the square root of 21.

So if this side of the square is
equal to the square root of 21, each of these squares are equal, so each one will
have a side length that is the square root of 21. So in order to find the entire side
length of the big square, we’ll need to add them all together. And there are eight of them, so the
square of 21 added together eight times or just eight multiplied to the square root
of 21. Therefore, the side length would be
eight square root 21 centimetres.