Cześć!
Obliczenia
[tex]A=(3,8)\longrightarrow x_A=3, \ y_A=8\\\\B=(5,7)\longrightarrow x_B=5, \ y_B=7\\\\|AB|=\sqrt{(x_B-x_A)^2+(y_B-y_A)^2}\\\\|AB|=\sqrt{(5-3)^2+(7-8)^2}\\\\|AB|=\sqrt{2^2+(-1)^2}\\\\|AB|=\sqrt{4+1}\\\\\huge\boxed{|AB|=\sqrt5}[/tex]
