The formula of a distance between two points:
[tex]A(x_A;\ y_A);\ B(x_B;\ y_B)\\\\AB=\sqrt{(x_B-x_A)^2+(y_B-y_A)^2}[/tex]
[tex](7,\ 2);\ (8,\ -3)\\\\d=\sqrt{(8-7)^2+(-3-2)^2}=\sqrt{1^2+(-5)^2}=\sqrt{1+25}=\sqrt{26}[/tex]
[tex](0,\ 5);\ (-7,\ 0)\\\\d=\sqrt{(-7-0)^2+(0-5)^2}=\sqrt{(-7)^2+(-5)^2}=\sqrt{49+25}=\sqrt{74}[/tex]
