Simple Fermat Factorization Example

Question

I'm trying to understand this example from wikipedia's Fermat's factorization method.

For example, to factor N = 5959, the first try for a is the square root of 5959 rounded up to the next integer, which is 78. Then, we try 79.

Try:    1       2      3
a      78      79      80
b^2    125     282     441
b      11.18   16.79   21

The third try produces the perfect square of 441. So, a = 80, b = 21, and the factors of 5959 are a - b = 59 and a + b = 101.

At this point, I understand the 80^2 - 5959 = 441, which is perfect square of 21.

At this point I'm not sure what to do.

Given this work so far, what are the final steps? And, what do we get from completing the final steps?

Answer 1

$80^2-5959=441$ rearranges to $80^2-21^2=5959$.

Then $5959=(80-21)(80+21)$.