19. Complete the two-column proof below. Given: AB = CB, AD = CD ; LABD = LCBD, LADB = LCDB Prove: AABD = ACBD Proof: A D Statements Reasons 1. AB = CB, AD = CD 1. 2 . BD = BD 2. Reflexive Prop. of Congruence 3. 3. Given 4 4. 5. AABD = ACBD 5 20. Write a coordinate proof to prove that in an isosceles right triangle, the segment from the vertex of the right angle to the A(0, 2a) midpoint of the hypotenuse is perpendicular to the hypotenuse. M Given: isosceles right AABC with right angle ZABC; M is the midpoint of AC. B(0, 0) Prove: BM LAC. C(2a, 0) x The Midpoint Formula shows that the coordinates of M are: The slope of AC is: The slope of BM is: The product of the slopes is SO