Value and simplify I want to find the value and simplify square root 36 ? 
Square root of 36 is 6 
But I would know how to find the value and simplify it . 

To find the square root of $37$ (say) involves a fair bit of calculation, and you will never get a numerically exact answer. But the situation is much different for $36$. For a rigorous proof that $\sqrt{36}=6$, all you need to do is (1) observe that $6^2=36$ and (2) note that $6$ is positive. Generally, a perfectly legitimate way to solve a mathematical problem is simply to guess the answer, if you are lucky enough to do so, and then verify that your guess is correct. 
