Chess board

1

If i ask you how many squares are there in the above  , generally your answer

will be 9.

Actually the exact answer is 14 (= 9+4+1)

Individually  9

By taking four squares at a time we get  4

Completely  1 

What can you say about the number of squares in chess board :

3

We have a formula to find the answer .Do you know that ?