Find the least nu

According to question,

In order to find the square root of the given number we will use the long division method.

Hence,

Using long division method,

The next natural number that is a perfect square can be obtained by squaring the next natural number of the obtained quotient i.e. 91

Therefore,

(91 + 1)² = (92)² = 8464

Hence,

The number that should be added to the given number to make it a perfect square:

= 8464 – 8400

= 64

Thus, the perfect square obtained is 8464 and its square root is 92