find the square root of 20.5209 by division method

1 answer

google the topic. Lots of examples and videos.
Just like division, finding roots is a guess and subtract method.
It's based on the fact that (a+b)^2 = a^2 + 2ab + b^2
So, you guess a, work out the rest, subtract, and go again.

If that makes no sense, read the online explanations and watch the videos.