| A | B |
|---|
| Theorem 6-1 Parallelogram: Opposite Sides | Opposite sides of a parallelogram are congruent. |
| Theorem 6-2 Parallelogram: Opposite Angles | Opposite angles of a parallelogram are congruent |
| Theorem 6-3 Parallelogram: Diagonals | The diagonals of a parallelogram bisect each other. |
| Theorem 6-4 Multiple Parallel Lines and a Transversal | If three (or more) parallel lines cut off congruent segments on one transversal, then they cut off congruent segments on every transversal. |
| Theorem 6-5 Converse Parallelogram Diagonals | If the diagonals of a quadrilateral bisect each other, then the quadrilateral is a parallelogram. |
| Theorem 6-6 Quadrilateral one pair of opposite sides | If one pair of opposite sides of a quadrilateral are both congruent and parallel, then the quadrilateral is a parallelogram. |
| Theorem 6-7 Converse Parallelogram Opposite Sides | If both pairs of opposite sides of a quadrilateral are congruent, then the quadrilateral is a parallelogram. |
| Theorem 6-8 Converse Parallelogram Opposite Angles | If both pairs of opposite angles of a quadrilateral are congruent, then the quadrilateral is a parallelogram. |
| Theorem 6-9 Diagonals of a Rhombus and angles | Each diagonal of a rhombus bisects two angles of the Rhombus. |
| Theorem 6-10 Diagonals of a Rhombus | The diagonals of a rhombus are perpendicular. |
