The vertices of triangle def are d(7, 3), e(4, -3), and f(10, -3). write a paragraph proof to prove that triangle def is isosceles.

I am given that the vertices of triangle DEF are D(7, 3), E(4, -3), and F(10, -3). Applying the distance formula to each pair of vertices in the triangle gives the following:

Two of the sides, DE and DF, have the same length. So, by definition of an isosceles triangle, triangle DEF is isosceles.