Rhombus plural: rhombi
Drag the orange dots on each vertex
to reshape the rhombus. Notice how the four sides remain the same length and the opposite sides remain parallel.
A rhombus is actually just a special type of parallelogram.
Recall that in a parallelogram each pair of opposite sides are equal in length.
With a rhombus, all four sides are the same length.It therefore has all the properties of a parallelogram.
See Definition of a parallelogram
Its a bit like a square that can 'lean over'
and the interior angles need not be 90°.
Sometimes called a 'diamond' or 'lozenge' shape.
Properties of a rhombus
||Any side can be considered a base. Choose any one you like. If used to calculate the area (see below) the corresponding altitude must be used.
In the figure above one of the four possible bases has been chosen.
||The altitude of a rhombus is the perpendicular distance
from the base to the opposite side (which may have to be extended). In the figure above, the altitude corresponding to the base CD is shown.
||There are several ways to find the area of a rhombus. The most common is (base × altitude).
Each is described in Area of a rhombus
||Distance around the rhombus. The sum of its side lengths.
See Perimeter of a rhombus
||Each of the two diagonals is the
of the other.
See Diagonals of a rhombus
Related polygon topics
Types of polygon
Area of various polygon types
Perimeter of various polygon types
Angles associated with polygons
(C) 2009 Copyright Math Open Reference. All rights reserved