Question: which one of the following numbers is a perfect square?
Answer: Natural numbers that are squares of other natural numbers are called perfect square or square number. For example; We know that; 1 = 1²; 4 = 2²; 9 = 3²; 16 = 4²; 25 = 5² and so on. Thus 1, 4, 9, 16, 25, etc., are perfect squares.