Check the picture below.
[tex]~~~~~~~~~~~~\textit{distance between 2 points} \\\\ (\stackrel{x_1}{-2}~,~\stackrel{y_1}{-4})\qquad (\stackrel{x_2}{4}~,~\stackrel{y_2}{1})\qquad \qquad d = \sqrt{( x_2- x_1)^2 + ( y_2- y_1)^2} \\\\\\ d=\sqrt{(~~4 - (-2)~~)^2 + (~~1 - (-4)~~)^2} \implies d=\sqrt{(4 +2)^2 + (1 +4)^2} \\\\\\ d=\sqrt{( 6 )^2 + ( 5 )^2} \implies d=\sqrt{ 36 + 25 } \implies d=\sqrt{ 61 }[/tex]
