Write true (T) or false (F) for the following statements. (i) The number of digits in a square numbers is even .
(ii) The square of a prime number is prime.
(iii) The sum of two square numbers is a square number.
(iv) The difference of two square numbers is a square number.
(v) The product of two square numbers is a square number.
(vi) No square number is negative
(vii) There is not square number between 50 and 60.
(viii) There are fourteen square number upto 200.
Take nine numbers forming a square in a calendar and mark the four numbers at the corners. Then the difference between the squares of the diagonal pairs is always ____.