Answer:
Step-by-step explanation:
Definition of perfect square: A perfect square is a number created by multiplying two of the same integers
25 is a perfect square: 25 is 5 multiplied by 5, which is the same integer multiplied twice
21 isn't a perfect square: 21 can be the result of multiplying 3 and 7, both of which are integers but aren't the same number.
