define perfect square in math

In mathematics, a perfect square is a number that can be obtained by multiplying an integer by itself. It is a non-negative integer that has a whole number square root.

For example, 9 is a perfect square because it can be expressed as 3 * 3 or (-3) * (-3). Similarly, 16 is a perfect square because it can be expressed as 4 * 4 or (-4) * (-4). On the other hand, numbers like 7 and 12 are not perfect squares since they cannot be expressed as the multiplication of an integer by itself.