Cześć!
Obliczenia
[tex]A=(2,1)\longrightarrow x_A=2, \ y_A=1\\\\B=(3,4)\longrightarrow x_ B=3, \ y_B=4\\\\|AB|=\sqrt{(x_B-x_A)^2+(y_B-y_A)^2}\\\\|AB|=\sqrt{(3-2)^2+(4-1)^2}\\\\|AB|=\sqrt{1^2+3^2}\\\\|AB|=\sqrt{1+9}\\\\\huge\boxed{|AB|=\sqrt{10}}[/tex]
