[tex]~~~~~~~~~~~~\textit{distance between 2 points} \\\\ A(\stackrel{x_1}{1}~,~\stackrel{y_1}{1})\qquad B(\stackrel{x_2}{4}~,~\stackrel{y_2}{1})\qquad \qquad AB = \sqrt{( x_2- x_1)^2 + ( y_2- y_1)^2} \\\\\\ AB=\sqrt{(4-1)^2+(1-1)^2}\implies AB=\sqrt{3^2-0^2}\implies AB=3 \\\\[-0.35em] ~\dotfill\\\\ B(\stackrel{x_1}{4}~,~\stackrel{y_1}{1})\qquad C(\stackrel{x_2}{4}~,~\stackrel{y_2}{5})\qquad \qquad BC=\sqrt{(4-4)^2+(5-1)^2} \\\\\\ BC=\sqrt{0^2+4^2}\implies BC=4 \\\\[-0.35em] ~\dotfill[/tex]
[tex]C(\stackrel{x_1}{4}~,~\stackrel{y_1}{5})\qquad A(\stackrel{x_2}{1}~,~\stackrel{y_2}{1})\qquad \qquad CA=\sqrt{(1-4)^2+(1-5)^2} \\\\\\ CA=\sqrt{(-3)^2+(-4)^2}\implies CA=\sqrt{3^2+4^2}\implies CA=5[/tex]
well, how many congruent sides? none, all three sides differ, meaning is an scalene triangle.
