2. A parallelogram is a
quadrilateral with opposite
sides parallel (and therefore
opposite angles equal). A
quadrilateral with equal sides
is called a rhombus, and
a parallelogram whose
angles are all right angles is
called a rectangle.
4. There are six important properties of parallelograms to
know:
1. Opposite sides are congruent (AB = DC).
2. Opposite angels are congruent (D = B).
3. Consecutive angles are supplementary (A + D =
180°).
4. If one angle is right, then all angles are right.
5. The diagonals of a parallelogram bisect each other.
6. Each diagonal of a parallelogram separates it into
two congruent triangles.
5. Quadrilateral Properties
Rhombus
Diagonally opposite angles are equal.
All sides are of equal lengths.
Opposite sides are parallel. The
diagonals bisect each other at 90°.
Rectangle
All angles are equal (90°). Opposite
sides are of equal length. The
diagonals are equal in length.
Parallelogram shapes