To understand rhomboid, we need to understand what is a plane figure. A plane figure can be an open or closed figure which is drawn using either straight line on curved lines. It is mostly a two-dimensional figure. So to understand geometry, we need to understand plane figures. They have both vertices and sides. Similarly, they have perimeters and areas but not surface area and volumes. The basic types of figures are as shown in the image below.

Also check: Parallelepiped


Definition of Rhomboid

The rhomboid is different than a rhombus. It is a type of parallelogram. It is very similar to parallelogram. It is a figure in which opposite sides are parallel to each other. This is why it is similar to parallelogram. And if a rhomboid has all sides equal, it becomes a rhombus. So we can say that a rhombus is always a rhomboid, but all rhomboid may not be a rhombus. Look at the image below to find the difference between a rhombus and a rhomboid.


Rhomboid Properties

  1. Opposite pair of sides are parallel.

Properties of Rhombus

  1. Opposite sides of a rhomboid are also congruent.

Properties of Rhombus

  1. The diagonal divides the rhomboid into two congruent triangles.

Properties of Rhombus

  1. Opposite angles of a rhomboid are also congruent.

Properties of Rhombus

  1. The sum of interior angles of a rhomboid is equal to 360 degrees.

Properties of Rhombus

Important Rhomboid Formulas

  • The perimeter of a rhomboid: The perimeter of a rhomboid is the sum of all sides of the figure i.e. P= (a +b + a +b) = 2(a + b), where b is the base of the rhomboid and a is the length of the other side of the rhomboid.

rhomboid perimeter and area

  • Area of a rhomboid: The diagonal of a rhomboid divides the rhomboid into two congruent triangles and its area becomes ½ x base x altitude.

Important Rhomboid Formulas

Where AB is the base and BD is the diagonal which divides it into two parts(equal).

Examples of a Rhomboid

Problem 1: Calculate the perimeter of the rhomboid shown below:

Example of Rhomboid

Solution: For the given figure above,

b = 8cm

a = 7 cm

h = 4 cm

Therefore,perimeter = 2 (a + b) cm = 2 (7 + 8) =2(15) = 30 cm


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