[tex]\bf ~~~~~~~~~~~~\textit{distance between 2 points} \\\\ A(\stackrel{x_1}{0}~,~\stackrel{y_1}{-8})\qquad B(\stackrel{x_2}{4}~,~\stackrel{y_2}{-5})\qquad \qquad d = \sqrt{( x_2- x_1)^2 + ( y_2- y_1)^2} \\\\\\ AB=\sqrt{[4-0]^2+[-5-(-8)]^2}\implies AB=\sqrt{(4-0)^2+(-5+8)^2} \\\\\\ AB=\sqrt{4^2+3^2}\implies AB=\sqrt{25}\implies AB=5[/tex]
