All rhombuses are parallelograms, but not all parallelograms are rhombuses. All squares are rhombuses, but not all rhombuses are squares. The opposite interior angles of rhombuses are congruent. Diagonals of a rhombus always bisect each other at right angles.

The Parallelogram A parallelogram has opposite sides parallel and equal in length. Also opposite angles are equal (angles “A” are the same, and angles “B” are the same). NOTE: Squares, Rectangles and Rhombuses are all Parallelograms!

An ordinary quadrilateral with no equal sides is not a parallelogram. A kite has no parallel lines at all. A trapezium and and an isosceles trapezium have one pair of opposite sides parallel. A Concave quadrilateral or arrowhead does not have parallel sides.

A rectangle is a quadrilateral in which all angles are right angles. A rectangle is a parallelogram, so its opposite sides are equal. The diagonals of a rectangle are equal and bisect each other.

Which information is NOT sufficient to prove that a parallelogram is a square? The diagonals are both congruent and perpendicular. The diagonals are congruent and one pair of adjacent sides are congruent.

Well, we must show one of the six basic properties of parallelograms to be true!

1. Both pairs of opposite sides are parallel.
2. Both pairs of opposite sides are congruent.
3. Both pairs of opposite angles are congruent.
4. Diagonals bisect each other.
5. One angle is supplementary to both consecutive angles (same-side interior)

Theorem 1: In a parallelogram, the opposite sides are of equal length. Theorem 2: If the opposite sides in a quadrilateral are the same length, then the figure is a parallelogram. Theorem 3: A quadrilateral is a parallelogram if and only if the diagonals bisect each other.

A parallelogram has four properties:

• Opposite angles are equal.
• Opposite sides are equal and parallel.
• Diagonals bisect each other.
• Sum of any two adjacent angles is 180°

A parallelogram is a quadrilateral that has its opposite sides parallel and equal to each other. It has its interior opposite angles equal. Also, the angles on the same side of transversal sum up to 180 degrees or supplementary to each other.

Terms in this set (5)

• Both pairs of opposite sides are parallel.
• Both pairs of opposite sides are congruent.
• Both pairs of opposite angles are congruent.
• Consecutive angles are supplementary.
• Diagonals bisect each other.

There are six important properties of parallelograms to know:

• Opposite sides are congruent (AB = DC).
• Opposite angels are congruent (D = B).
• Consecutive angles are supplementary (A + D = 180°).
• If one angle is right, then all angles are right.
• The diagonals of a parallelogram bisect each other.

What is another word for parallelogram?

In a parallelogram, opposite sides are equal, opposite angles are equal and diagonals bisect each other. A quadrilateral can be constructed uniquely if its two adjacent sides and three angles are given. • A quadrilateral can be constructed uniquely if its three sides and two included angles are given.

Parallelogram Symbols

What does a parallelogram flowchart symbol mean? A parallelogram represents data in a flowchart. Data is either input a process requires or an output that the process hands off to the next step.

A parallelogram has no lines of symmetry. It has rotational symmetry of order two.

Common Symbols Used in Geometry

Side-Side-Side is a rule used to prove whether a given set of triangles are congruent. The SSS rule states that: If three sides of one triangle are equal to three sides of another triangle, then the triangles are congruent.