A perfect square is a number that can be expressed as the square of an integer. In other words, a number is a perfect square if its square root is an integer.

Example	Rewrite as a Product	Perfect Square?	Explanation
$25$	$5\times 5=5^2$	Yes $✓$	$5$ is an integer.
$30.25$	$5.5\times 5.5=5.5^2$	No $\times$	$5.5$ is not an integer.
$32$	$4\sqrt{2}\times 4\sqrt{2}=(4\sqrt{2}{)}^2$	No $\times$	$4\sqrt{2}$ is not an integer.
$64$	$8\times 8=8^2$	Yes $✓$	$8$ is an integer.

Similarly, suppose a variable has an even exponent. In that case, it is still considered a perfect square because this condition guarantees that the variable can be rewritten as the product of two identical powers with integer exponents.