Review of Quadrilaterals
Read this chapter, which summarizes all properties of various quadrilaterals, including the properties of their diagonals.
Parallelogram
A parallelogram is a quadrilateral with two pairs of parallel sides.
The Properties of a Parallelogram:
1. Opposite sides are parallel, i.e., and .
2. Opposite sides are congruent, i.e., and .
3. Opposite angles are congruent, i.e., and .
4. Adjacent angles are supplementary, i.e., , , and .
5. Diagonals bisect each other, i.e., and .
6. Each diagonal bisects the parallelogram, i.e., divides it into two congruent triangles and .