If the area of a square has increased by a factor of 16, by how much has each side increased?

4 times

Explanation: If the area of a square has increased by a factor of 16,

Let us consider, the area of an old square is A and its side is .

Now, the area of a new square is 16 A and its side is

Now, we take a ratio of area of the old and new square

So, we can say that the sides of new square is 4 times of the sides of old square.