has vertices D(1, 3), E(3, –1), and F(–2, –1). Determine if is an equilateral, isosceles, or scalene triangle.
isosceles, reason why, two -1 y-values. for a right triangle, two x-values and 2 y-values need to be the same.
Distance b/n D&E =sqrroot(20)
hence two sides of a triangle are equal it is isosceles