### Theory:

• A rhombus is a quadrilateral (plane figure, closed shape, four sides) with four equal-length sides and opposite sides are parallel to each other.
• The opposite interior angles of rhombuses are congruent.
• The diagonals of a rhombus bisect each other at right angles.

How does a Rhombus look?
• A plane figure (it has two dimensions)
• A closed shape (it has an interior and exterior)
• A quadrilateral (four-sided plane figure with straight sides)

Is a Square a Rhombus?
• All squares are rhombuses, but not all rhombuses are squares.

Is a Rhombus a Parallelogram?
• All rhombuses are parallelograms, but not all parallelograms are rhombuses.
Properties of a Rhombus:
 Side All sides of the rhombus are equal.The opposite sides of a rhombus are parallel. Angle The opposite angles of a rhombus are equal.The sum of two adjacent angles is equal to 180 degrees. Diagonals The diagonals bisect each other at right angles.The two diagonals of a rhombus form four right-angled triangles which are congruent to each other. Altitude The altitude of a rhombus is the perpendicular distance from the base to the opposite side.

Rhombus Applications:
• The rhombus can be used as traffic signs or as the windows on the motorcycle or cars.