Rhombus, Kite, or Diamond? The properties, the formulas, and absolutely everything you need to know

What's its name? Rhombus, kite, or diamond? ;)

Between us... it doesn't matter. It's about that mysterious geometric figure that reminds us of a precious diamond or a deck of cards... Whatever you call it, you must know the properties of this figure and its uniqueness to solve certain geometric problems. So, let's begin...

Rhombus

R - Rhombus

Practice Rhombus for ninth grade

Examples with solutions for Rhombus for ninth grade

Exercise #1

Given the rhombus in the drawing:

444777

What is the area?

Video Solution

Step-by-Step Solution

Let's remember that there are two ways to calculate the area of a rhombus:

The first is the side times the height of the side.

The second is diagonal times diagonal divided by 2.

Since we are given both diagonals, we calculate it the second way:

7×42=282=14 \frac{7\times4}{2}=\frac{28}{2}=14

Answer

14

Exercise #2

Look at the rhombus in the figure.

What is the relationship between the marked angles?

BAAB

Step-by-Step Solution

Let's remember the different definitions of angles:

Corresponding angles are angles located on the same side of the line that intersects the two parallels and are also situated at the same level with respect to the parallel line they are adjacent to.

Therefore, according to this definition, these are the angles marked with the letter A

Alternate angles are angles located on two different sides of the line that intersects two parallels, and which are also not at the same level with respect to the parallel they are adjacent to.

Therefore, according to this definition, these are the angles marked with the letter B

Answer

A - corresponding; B - alternate

Exercise #3

Look at the rhombus in the figure.

What is its area?

P=50P=50P=50888

Video Solution

Step-by-Step Solution

First, let's remember that according to the properties of a rhombus, all sides of a rhombus are equal,

Therefore, if we define the sides of the rhombus with the letters ABCD,

We can argue that:

AB=BC=CD=DA

We use the perimeter formula:

50 = AB+BC+CD+DA

And we can conclude that
 4AB=50

(We can also use any other side, it doesn't matter in this case because they are all equal.)

 

We divide by four and reveal that:

AB=BC=CD=DA = 12.5

 

Now let's remember the formula for the area of a rhombus: the height times the side corresponding to the height.

We are given the length of the external height 8,

Now, we can replace in the formula:

8*12.5=100

Answer

100 cm²

Exercise #4

Using the rhombus in the drawing:

555333

Calculate the area?

Video Solution

Step-by-Step Solution

Remember there are two options to calculate the area of a rhombus:

1: The diagonal multiplied by the diagonal divided by 2.

2: The base multiplied by the height.

In the question, we are only given the data for one of the diagonals and one of the sides, which means we cannot use either of the above formulas.

We need to find more data. Let's begin by finding the second diagonal:

Remember that the diagonals of a rhombus are perpendicular to one another, which means that they form a 90-degree angle.

Therefore, all the triangles in a rhombus are right-angled.

Now we can focus on the triangle where the side and the height are given, and we will calculate the third side using the Pythagorean theorem:

a2+b2=c2 a²+b²=c² Insert the given data:

32+x2=52 3^2+x^2=5^2 9+x2=25 9+x^2=25 x2=259=16 x^2=25-9=16 x=16=4 x=\sqrt{16}=4

Now that we have found the second half of the diagonal, we can calculate the area of the rhombus by multiplying the two diagonals together.

Since the diagonals in a rhombus are perpendicular and cross each other, they are equal. Hence, our diagonals are equal:

3+3=6 3+3=6 4+4=8 4+4=8 Therefore, the area of the rhombus is:

6×82=482=24 \frac{6\times8}{2}=\frac{48}{2}=24

Answer

24

Exercise #5

A rhombus has a side length measuring 7 cm.

Is DC equal to 8 cm?

777AAABBBDDDCCC

Video Solution

Step-by-Step Solution

Let's recall the properties of a rhombus. In a rhombus, all sides are equal to each other, therefore DC cannot be equal to 8 cm.

Additionally, in a rhombus, there are 2 pairs of parallel and equal sides. Since the side parallel to AB is CD, it must be equal to 7 cm.

Answer

No

Exercise #6

A rhombus and its external height are shown in the figure below.

The length of each side of the rhombus is 5 cm.

What is its area?

333

Video Solution

Answer

15 cm².

Exercise #7

In the drawing given a rhombus

The length of each side of the rhombus is 5 cm

The length of the height of the side is 3 cm

What is the area of the rhombus?

555555555555333

Video Solution

Answer

15 cm².

Exercise #8

Calculate the area of the rhombus in the figure below:

555222

Video Solution

Answer

10 cm²

Exercise #9

Given the rhombus in the figure

What is your area?

999999999999444

Video Solution

Answer

36 cm².

Exercise #10

Look at the rhombus in the figure.

What is its area?

777666

Video Solution

Answer

42 cm²

Exercise #11

Given the rhombus whose length of its sides is 8 cm

The length of the given height is 5 cm

What is the area of the rhombus?

888555

Video Solution

Answer

40 cm²

Exercise #12

Look at the rhombus in the diagram below.

What is the area of the rhombus?

555333

Video Solution

Answer

7.5 cm²

Exercise #13

Given the rhombus in the figure

What is your area?

101010888

Answer

80 cm²

Exercise #14

In the drawing given a rhombus

The length of the main diagonal 6 cm

The length of the secondary diagonal 4 cm

What is the area of the rhombus?

666444

Video Solution

Answer

12 cm²

Exercise #15

Given the rhombus in the drawing:

888131313

What is the area?

Video Solution

Answer

52