Question

Find the greatest number of four
digits which is a perfect square.​

Answer 1

Answer:

$\sqrt{9801}$

is the only greatest four digit perfect square

Answer 2

$\rm\huge \color{salmon}Answer:$

9801

$\rm\huge \color{salmon} Explanation:$

The square root of a four-digit number is always a two digit number. Thus, the greatest four-digit perfect square number will be the square of the biggest two digit number.

The biggest two-digit number is 99.

Therefore, the greatest four-digit number will be $\sf {99}^{2} =9801$