Points are
[tex]\\ \sf\longmapsto \sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]
[tex]\\ \sf\longmapsto \sqrt{(4+2)^2+(4+2)^2}[/tex]
[tex]\\ \sf\longmapsto \sqrt{6^2+6^2}[/tex]
[tex]\\ \sf\longmapsto \sqrt{36+36}[/tex]
[tex]\\ \sf\longmapsto \sqrt{72}[/tex]
[tex]\\ \sf\longmapsto 8.4[/tex]
