Find the largest number of 2 digits which is a perfect square.
Let us take the first 3-digit number
First 3-digit number = 100
Now,
We know that,
100 is a perfect square.
And,
Its square root is 10.
Now,
The number before 10 is 9.
Square of 9 = 81
Hence,
The largest 2-digit number which is a perfect square is 81.