Question

question 6 of 10 which of the following are necessary when proving that the opposite sides of a parallelogram are congruent? check all that apply. a. alternate interior angles are supplementary. b. opposite sides are perpendicular. c. opposite sides are parallel. d. alternate interior angles are congruent.

Explanation:

To prove opposite sides of a parallelogram are congruent, start with its definition (opposite sides parallel, C). Drawing a diagonal creates triangles. By parallel sides, alternate interior angles are congruent (D), enabling triangle congruence (ASA/SAS), thus proving sides congruent. A is false (alternate interior angles are congruent, not supplementary); B is irrelevant (not a property of parallelograms).

Answer:

C. Opposite sides are parallel, D. Alternate interior angles are congruent.