which of the following are necessary when proving the opposite angles of a parallelogram are congruent? Check all that apply.A) Opposite sides are perpendicular B) Corresponding parts of similar triangles are similar C) Opposite sides are congruent D) Corresponding parts of congruent triangles are congruent

Answer;Opposite sides are congruent  Corresponding parts of congruent triangles are congruentExplanation;A parallelogram is a quadrilateral that possess two pairs of opposite sides that are equal in length and parallel to each other. Additionally, the diagonals of a parallelogram bisects each other. The opposite angles of a parallelogram are congruent this can be proved by the fact that; Opposite sides are congruent  Corresponding parts of congruent triangles are congruent