Using the Pythagorean Theorem, the distance between these two points can be found!
[tex] {a}^{2} + {b}^{2} = {c}^{2} [/tex]
5-2 is 3
6-2 is 4
Now:
[tex] {3}^{2} + {4}^{2} = {c}^{2} \\ 9 + 16 = {c}^{2} \\ 25 = {c}^{2} \\ 5 = c[/tex]
(This is my take on it, anyway..)