Question

give a reason why square of 21 is odd​

Answer 1

Answer:

because it is a odd number

Answer 2

Answer:

Odd numbers always end with a digit of 1, 3, 5, 7, or 9. 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31 are odd numbers.