Question

given: abcd is a parallelogram. prove: ∠a and ∠d are supplementary. by the definition of a parallelogram, ab∥dc. ad is a transversal between these sides, so ∠a and ∠d are same - side interior angles. because ab and dc are the same - side interior angles must be by the same - side interior angles congruent opposite parallel perpendicular, ∠a and ∠d are supplementary.

Explanation:

In a parallelogram, when two parallel - sides are cut by a transversal, same - side interior angles are supplementary. In parallelogram ABCD, AB || DC and AD is a transversal. ∠A and ∠D are same - side interior angles.

Answer:

Parallel