Rhombus

(Jump to Area of a Rhombus or Perimeter of a Rhombus)

A Rhombus is a flat shape with 4 equal straight sides.

A rhombus looks like a diamond

	All sides have equal length
	Opposite sides are parallel, and opposite angles are equal (it is a Parallelogram).
	The altitude is the right angle distance between opposite sides
	And the diagonals "p" and "q" of a rhombus bisect each other at right angles.

Play with a rhombus:

Area of a Rhombus

The Area can be calculated by:

• the altitude times the side length:
  Area = altitude × s
• the side length squared (s²) times the sine of angle A (or angle B):
  Area = s² sin(A)
  Area = s² sin(B)
• by multiplying the lengths of the diagonals and then dividing by 2:
  Area = (p × q)/2

If you can draw your Rhombus, try the Area of Polygon by Drawing tool.

Perimeter of a Rhombus

The Perimeter is the distance around the edges.

The Perimeter is 4 times "s" (the side length) because all sides are equal in length: Perimeter = 4s

Is a Square a Rhombus?

Yes, because a square is just a rhombus where the angles are all right angles.

Names

It is more common to call this shape a rhombus, but some people call it a rhomb or even a diamond.

The plural is rhombi or rhombuses, and, rarely, rhombbi or rhombbuses (with a double b).

The name "rhombus" comes from the Greek word rhombos: a piece of wood whirled on a string to make a roaring noise! What we might call a "bullroarer".