Answer:
See below.
Step-by-step explanation:<
< DAC and < BCA are alternate angles. So as they are congruent the 2 sides AD and BC are parallel.
Similarly as < BAC and DCA are congruent the sides AB and DC are parallel, so ABCD is a parallelogram.
Therefore as its opposite sides are congruent and AC is common to both triangles, triangle s ABC and CDA are congruent by SSS.