Answer: 100.
Justification.
A perfect square is a number that can be expressed and the square of an integer.
In this case, 10^2 = 100, so 100 is a perfect square.
It is a good idea to memorize the first perfect squares. I recommend you memorize the squares of the numbers from 1 to 14. That will help you a lot in some standardized tests,which requires to answer some quesitons fast:
