There are many shapes which give the impression of being similar to each other, but when you look at it, there are very few differences between them. Same is the case with a rhombus and parallelogram which are closely related but still different. The main variation between them can be explained such as a rhombus is a quadrilateral all of whose sides have the same length. On the other hand, a quadrilateral whose opposite sides are both parallel and equal in length will be known as a parallelogram. A rhombus will always be a parallelogram, but that is not true vice versa.

### Comparison Chart

Basis of Distinction |
Rhombus |
Parallelogram |

Definition |
A quadrilateral all of whose sides have the same length. | A quadrilateral whose opposite sides are both parallel and equal in length. |

Formula |
(x/a) + (y/b) = 1. | K = bh |

Origin |
Latin language word rhombus meaning “to turn round and round.” | Greek language word parallelogrammon meaning “of parallel lines.” |

Characteristic |
All four sides of the same length even if short or long. | Two long sides of the same length and two short sides of the same length. |

Co-relation |
Every rhombus will be a parallelogram. | Every parallelogram will not be a rhombus. |

### What is Rhombus?

This can be defined as a quadrilateral all of whose sides have the same length. The word itself is derived from the Latin language and is one of those rare ones who has stayed the way they are since the integration in the 16^{th} century and had the meaning of “to turn round and round.” It has another name as well which is equilateral quadrilateral since equilateral is a term which means all the sides are of the same length. It is also referred as a diamond especially while playing cards in which the diamond-like shape is known to look like an octahedral or in some cases like a rhombus with an angle of 60 degrees. It is safe to say that every object which is rhombus is also a parallelogram and looks like a kite. It can also be assumed that every rhombus with right angles is known as a square.

There are many ways in which it can be distinguished, the first one being the simple most definition according to which a quadrilateral with all four sides is a rhombus. Any quadrilateral in which the diagonals bisect each other and are perpendicular is also the definition of a rhombus. Another way of characterizing it is that any quadrilateral in which each diagonal bisect the two opposite sides of the interior angles is known as a rhombus. It is also explained regarding geometry as a quadrilateral ABCD which has a standard point O in its plane and forms four concurrent triangles ABO, BCO, CDO, and DAO. It can be expressed in terms of the equation which is (x/a) + (y/b) = 1.

### What is Parallelogram?

It ca be defined as a quadrilateral whose opposite sides are both parallel and equal in length. It is similar to a rhombus but different at the same time and has some distinctive properties which are that of a rectangle. It can be explained as a simple four sided object which has two sides parallel to each other. The sides from left and right will be equal to each other while the sides from up and down will be equal to each other but all four of them will not be of the same length. The word was originated from the Greek language term parallelogrammon and meant “of parallel lines.” There are some special cases for this term which are that if two sides are of equal length and the other two are of different lengths from each other, then it is known as a trapezoid. Similarly, if the opposite sides are parallel to each other and the adjacent sides are unequal then the rights angles will not exist, this case is called rhomboid. A rhombus is another part which fits in this, and as explained earlier, every rhombus will be a parallelogram. There are some ways according to which it can be characterized. For a shape to be a parallelogram, two pairs of opposite sides should be equal in length. Another case would be that two pairs of different angles should be equal when they are measured. The diagonals should bisect each other, and there are many other cases with which it can be proved. The main formula of finding the area is rather simple and is denoted as K = bh.

### Key Differences between Rhombus and Parallelogram

- All four sides are of the same length in case of a rhombus while all four sides are not of the same length in the event of a parallelogram.
- There are two sides of the same length which will be long, and two sides of the same length which will be short for a parallelogram while rhombus has all the four sides either long or short but equal.
- There will be two acute and two obtuse angles in a rhombus while same will be the case for a parallelogram.
- Every rhombus will be a parallelogram while every parallelogram will not be a rhombus.
- There will be two pairs of parallel lines in case of parallelogram while there will be two pairs of equal length in a rhombus as well.
- The term rhombus has been originated from the Latin language and has stayed the same word with the meaning of “to turn round and round.” The term parallelogram has been originated from Greek language word parallelogrammon with the meaning of “of parallel lines.”
- The term rhombus can be explained in terms of equation as (x/a) + (y/b) = 1. On the other hand, the term parallelogram can be expressed as K = bh.