Answer:
m∠DAB is 114°
Step-by-step explanation:
The given parameters are;
The dimensions of the given parallelogram ABCD are AD = 19, EC = 15, m∠ABC = 66°, m∠DAC = 78°, m∠BDC = 19°
Given that in parallelogram ABCD, the same side interior angles are supplementary, we have;
m∠ABC and m∠DAB are supplementary
Therefore;
m∠ABC + m∠DAB = 180° by definition of supplementary angles
66° + m∠DAB = 180°
m∠DAB = 180° - 66° = 114°
m∠DAB = 114°.
