[tex]~\hfill \stackrel{\textit{\large distance between 2 points}}{d = \sqrt{( x_2- x_1)^2 + ( y_2- y_1)^2}}~\hfill~ \\\\[-0.35em] ~\dotfill\\\\ A(\stackrel{x_1}{-1}~,~\stackrel{y_1}{4})\qquad B(\stackrel{x_2}{2}~,~\stackrel{y_2}{2}) ~\hfill AB=\sqrt{(~~ 2- (-1)~~)^2 + (~~ 2- 4~~)^2} \\\\\\ ~\hfill AB=\sqrt{( 3)^2 + ( -2)^2}\implies \boxed{AB=\sqrt{13}} \\\\\\ B(\stackrel{x_1}{2}~,~\stackrel{y_1}{2})\qquad C(\stackrel{x_2}{-2}~,~\stackrel{y_2}{-1}) ~\hfill BC=\sqrt{(~~ -2- 2~~)^2 + (~~ -1- 2~~)^2}[/tex]
[tex]~\hfill BC=\sqrt{( -4)^2 + ( -3)^2}\implies \boxed{BC=5} \\\\\\ C(\stackrel{x_1}{-2}~,~\stackrel{y_1}{-1})\qquad A(\stackrel{x_2}{-1}~,~\stackrel{y_2}{4}) ~\hfill CA=\sqrt{(~~ -1- (-2)~~)^2 + (~~ 4- (-1)~~)^2} \\\\\\ ~\hfill CA=\sqrt{( 1)^2 + (5)^2}\implies \boxed{CA=\sqrt{26}} \\\\[-0.35em] ~\dotfill\\\\ \stackrel{Perimeter}{\sqrt{13}~~ + ~~5~~ + ~~\sqrt{26} ~~ \approx ~~ \text{\LARGE 14}}[/tex]
