Discover the best answers at Westonci.ca, where experts share their insights and knowledge with you. Experience the ease of finding reliable answers to your questions from a vast community of knowledgeable experts. Connect with a community of professionals ready to provide precise solutions to your questions quickly and accurately.

Given: ABCD is a parallelogram.

Prove: ∠A and ∠D are supplementary.

Parallelogram A B C D is shown.

By the definition of a parallelogram, AB∥DC. AD is a transversal between these sides, so ∠A and ∠D are
angles. Because AB and DC are
, the same-side interior angles must be
by the same-side interior angles theorem. Therefore, ∠A and ∠D are supplementary.