Final answer:
To prove that ∆ABM is congruent to ∆DCM, we can use the fact that AB = CD, AM = DM and the fact that the included angles are equal.
Step-by-step explanation:
To prove that ∆ABM is congruent to ∆DCM, we can show that AB = CD, AM = DM, and that the included angle between AB and AM is equal to the included angle between CD and DM.
To show that AB = CD, we can use the fact that AB = AC.
To show that AM = DM, we can use the fact that MA = MD.
Finally, to show that the included angles are equal, we can use the fact that the two triangles share the same base, AC, and the included angles are vertical angles.