The diagonals of a rhombus have 3 properties that we can use without having to prove them:

The diagonals of a rhombus have 2 properties that we must prove to use them:

Other properties:

  • The lengths of the diagonals of a rhombus are not equal.

The product of the diagonals divided by 2 is equal to the area of the rhombus:
product of the diagonals2=area of rhombus\frac{product~of~the~diagonals}{2}=area~of~rhombus

Diagonals of a rhombus

A - Diagonals of a rhombus

Suggested Topics to Practice in Advance

  1. Rhombus, kite, or diamond?

Practice Diagonals of a Rhombus

Examples with solutions for Diagonals of a Rhombus

Exercise #1

Look at the following rhombus:

Are the diagonals of the rhombus parallel?

Step-by-Step Solution

The diagonals of the rhombus intersect at their point of intersection, and therefore are not parallel

Answer

No.

Exercise #2

Look at the following rhombus:

Are the diagonals of the rhombus perpendicular to each other?

Step-by-Step Solution

The diagonals of the rhombus are indeed perpendicular to each other (property of a rhombus)

Therefore, the correct answer is answer A.

Answer

Yes.

Exercise #3

Look at the rhombus below:

Do the diagonals of the rhombus form 4 congruent triangles?

Step-by-Step Solution

First, let's mark the vertices of the rhombus with the letters ABCD, then draw the diagonals AC and BD, and mark their intersection point with the letter E:

AAABBBCCCDDDEEE

Now let's use several facts and properties:

a. The rhombus is a type of parallelogram, therefore its diagonals intersect each other, meaning:

AE=EC=12ACBE=ED=12BD AE=EC=\frac{1}{2}AC\\ BE=ED=\frac{1}{2}BD\\

b. A property of the rhombus is that its diagonals are perpendicular to each other, meaning:

ACBDAEB=BEC=CED=DEA=90° AC\perp BD\\ \updownarrow\\ \sphericalangle AEB=\sphericalangle BEC=\sphericalangle CED=\sphericalangle DEA=90\degree

c. The definition of a rhombus - a quadrilateral where all sides are equal, meaning:

AB=BC=CD=DA AB=BC=CD=DA

Therefore, from the three facts mentioned in: a-c and using the SAS (Side-Angle-Side) congruence theorem, we can conclude that:

d.
AEBCEBAEDCED \triangle AEB\cong\triangle CEB\cong\triangle AED\cong\triangle CED (where we made sure to properly and accurately match the triangles according to their vertices in correspondence with the appropriate sides and angles).

Indeed, we found that the diagonals of the rhombus create (together with the rhombus's sides - which are equal to each other) four congruent triangles.

Therefore - the correct answer is answer a.

Answer

Yes

Exercise #4

Do the diagonals of the rhombus above intersect each other?

Step-by-Step Solution

In a rhombus, all sides are equal, and therefore it is a type of parallelogram. It follows that its diagonals indeed intersect each other (this is one of the properties of a parallelogram).

Therefore, the correct answer is answer A.

Answer

Yes

Exercise #5

Given the rhombus:

BBBAAACCCDDD50

How much is it worth? A ∢A ?

Video Solution

Step-by-Step Solution

The rhombus is a type of parallelogram, therefore its opposite angles are equal (property of parallelograms), so:

A=50° ∢A =50\degree Therefore, the correct answer is answer A.

Answer

50

Exercise #6

Look at the following rhombus:

Can a rhombus have diagonals that are equal?

Video Solution

Answer

Yes.

Exercise #7

Given the rhombus:

BBBAAACCCDDD30

How much is it worth? D ∢D ?

Video Solution

Answer

30

Exercise #8

Given the rhombus:

BBBAAACCCDDD50

How much is it worth? A ∢A ?

Video Solution

Answer

50

Exercise #9

Given the rhombus:

BBBAAACCCDDD130

How much is it worth? B ∢B ?

Video Solution

Answer

130

Exercise #10

Given the rhombus:

Is every rhombus a square?

Video Solution

Answer

Not true

Exercise #11

Given the rhombus:

Is every square a rhombus?

Video Solution

Answer

True

Exercise #12

Given the rhombus:

BBBAAACCCDDD60

How much is it worth? D ∢D ?

Video Solution

Answer

60

Exercise #13

Given the rhombus:

BBBAAACCCDDD80

How much is it worth? C ∢C ?

Video Solution

Answer

160

Exercise #14

Given the rhombus:

BBBAAACCCDDD55

How much is it worth? A ∢A ?

Video Solution

Answer

70

Exercise #15

Given the rhombus:

BBBAAACCCDDD20

How much is it worth? B ∢B ?

Video Solution

Answer

140