Answer:
m<DCB = 84°
Explanation:
ABCD is a parallelogram since it has two sets of parallel sides.
Opposite angles in a parallelogram are congruent.
Consecutive angles in a parallelogram are supplementary.
<DCB is consecutive to <D.
m<DCB + m<D = 180°
m<DCB + 96° = 180°
m<DCB = 84°