[tex]\dag\bf\:A(x_1,y_1)=(1,5)[/tex]
[tex]\dag\bf\:B(x_2,y_2)=(3,13)[/tex]
We have to find distance between point A and point B[tex].[/tex]
[tex]\bigstar\:\boxed{\bf{AB=\sqrt{(x_2-x_1)^2+(y_2+y_1)^2}}}[/tex]
[tex]:\implies\tt\:AB=\sqrt{(3-1)^2+(13-5)^2}[/tex]
[tex]:\implies\tt\:AB=\sqrt{(2)^2+(8)^2}[/tex]
[tex]:\implies\tt\:AB=\sqrt{4+64}[/tex]
[tex]:\implies\tt\:AB=\sqrt{68}[/tex]
[tex]:\implies\tt\:AB=\sqrt{4(17)}[/tex]
[tex]:\implies\underline{\boxed{\bf{\red{AB=2\sqrt{17}\:unit}}}}[/tex]