1. Chapter 5 -- Quadrilaterals
Section 5-1 – parallelograms

2. Definition of a Parallelogram
A quadrilateral with parallel opposite sides
Note: parallel sides mean same-side interior
angles are supplementary.
Complete Sample Problem 1

3. Properties of parallelograms
Opposite sides of a parallelogram are congruent.
Complete Sample Problem 2

4. Properties of parallelograms
Opposite angles of a parallelogram are congruent.
Complete Sample Problem 3

5. Properties of parallelograms
Diagonals of a parallelogram bisect each other.
Complete Sample Problem 4