Respuesta :
With DC = AB, you have a pair of sides.
Then with the parallel lines, you get angles 2 and 3 are congruent because they are alternate interior angles.
Finally, side AC is congruent to side AC. That gives you another pair of congruent sides.
You can use SAS.
Then with the parallel lines, you get angles 2 and 3 are congruent because they are alternate interior angles.
Finally, side AC is congruent to side AC. That gives you another pair of congruent sides.
You can use SAS.