The difference between a parallelogram and a rhombus is that a parallelogram is a quadrilateral whose opposite sides are parallel to one another regardless of how many sides the figure has, and a rhombus is a parallelogram that has four sides with two opposites sides that are equal to one another. When all sides of the parallelogram are equal but have angles that are not equal to 90 degrees, it is also called a rhombus.
Every rhombus is a parallelogram, but not every parallelogram is a rhombus. A rhombus that has straight sides and 90-degree angles is simply called a square.
A rhombus and a parallelogram are both considered quadrilaterals. A quadrilateral is any shape with four sides. Squares and rectangles also fit this criteria. A rhombus is a square that is leaning, while a parallelogram is a rectangle that leans. Unlike squares and rectangles, neither a rhombus nor a parallelogram have angles that equal 90 degrees, which makes them easier to recognize.
A good example of a rhombus is a diamond. The shape of a diamond has four equal sides that seem to be angled either up, down or to one side. An example of a parallelogram is a kite. The two top sides of the kite are equal to each other as are the two bottom sides, but the opposite sides are parallel to each other.
Just like a square, rectangle or any other quadrilateral, the area of the object can be found by multiplying the length of the object by its width. Regardless of whether the object is a rhombus, parallelogram, square or rectangle, the interior angles always add up to 360 degrees.