Atriangle has vertices (2, 5), (8, 3), and (2, 1). classify the triangle by its angles and its sides. acute isoscelesright equilateralacute equilateralright isosceles

How these points appear in xy plane, is shown in the attached picture. If we calculate the distances using the formula for the distance of between two points, , where  , and ,   are the coordinates of the points. We find that the distance from the point (8;3) to (2;5) and to (2;1) is equal. And that's why it is an isosceles triangle.