Question: Definition of Parallelogram

Answer: A quadrilateral with both pairs of opposite sides parallel

Question: Parallelogram Opposite Sides Theorem

Answer: If a quadrilateral is a parallelogram, then both pairs of its opposite sides are congruent

Question: Parallelogram Opposite Angles Theorem

Answer: If a quadrilateral is a parallelogram, then both pairs of its opposite angles are congruent

Question: Parallelogram Consecutive Angles Theorem

Answer: If a quadrilateral is a parallelogram, then its consecutive angles are supplementary.

Question: Parallelogram Diagonals Theorem

Answer: if a quadrilateral is a parallelogram, then both pairs of its diagonals bisect each other