To be able to classify the triangle you have to plot it
You can calculate the length of the sides as follows:
[tex]\begin{gathered} AC=\sqrt[]{(-1+3)^2+(5-2)^2} \\ AC=\sqrt[]{13} \end{gathered}[/tex][tex]\begin{gathered} AB=\sqrt[]{(5-4)^2+(2+3)^2} \\ AB=\sqrt[]{26} \end{gathered}[/tex][tex]\begin{gathered} BC=\sqrt[]{(2+1)^2+(4-2)^2} \\ BC=\sqrt[]{13} \end{gathered}[/tex]Sides AC and BC are equal.
You can classify this triangle as an isosceles triangle