The area of a square is given by the formula



So we substitute 100 for A:



Now we take the square root of both sides:





That means each side of the square is 10

Perimeter means the distance all the way around the figure.

A square has 4 sides, and each of those 4 sides is 10.


Notice that the left side is 10.
Notice that the top side is 10.
Notice that the right side is 10.
Notice that the bottom side is 10.

Now notice that when you add all the way around you get

10 + 10 + 10 + 10 = 40.

That shows that the perimeter, which is how far it is all
the way around the square is 40.  So the answer is 40.

Edwin