Keenan wants to use the figure below to prove that the midsegment of a triangle is parallel to the third side of that triangle. A triangle ABC with its points A(0,0), B(2k, 0), and C(2g,2h). D, E, and F are the midpoint of the sides AC, BC, AB, respectively, and it forms dotted triangle DEF. Which of the following statements is true and should be included in his proof?