[tex]|AB|=\sqrt{(x_B-x_A)^2+(y_B-y_A)^2}\\\\|AB|=\sqrt{(-1-(-10))^2+(-2-(-1))^2}\\|AB|=\sqrt{(-1+10)^2+(-2+1)^2}\\|AB|=\sqrt{9^2+(-1)^2}\\|AB|=\sqrt{81+1}\\\boxed{|AB|=\sqrt{82}\,[j]}[/tex]
