Perimeter

🏆Practice perimeter of a triangle

What is the perimeter?

The perimeter indicates the distance we will walk if we start from a certain point, complete a full lap, and return exactly to the starting point.
For example, if we are asked what the perimeter of the waist is, we will take a tape measure and measure the perimeter from a certain point until completing a full lap and returning to the same point from which we started the measurement.
It works exactly the same way in mathematics. The perimeter of any shape is the distance from a specific point back to it after having completely surrounded it.
If this is our figure:

What is the perimeter

Its perimeter will be the distance we cover if we travel along its line from a certain point, and return to it after making a full lap. Imagine that you are surrounding the figure:


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Test yourself on perimeter of a triangle!

einstein

AB = 10.5

CD = 13

AC = 7.5

BD = 7.5

Calculate the perimeter of the rectangle ABCD.

10.510.510.57.57.57.51313137.57.57.5AAABBBDDDCCC

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Units of Measurement for Perimeter

The perimeter is measured in units of mm, cm, or meters, according to what the question states.
Generally, most figures are given in units of cm.
We can convert the different units of measure in the following way:
11 cm = 1010 mm
11 meter = 100100 cm

Now we will learn to calculate the perimeter of the most known figures. Are we ready?
How is the perimeter calculated in general?
All the lengths of the edges (or sides) of the figure are added together.
The sum of all the edges is the perimeter.


Perimeter of the Square

A2 - Perimeter of the square = 4a

aa -> Side of the square
In the square, all sides are equal, therefore, its perimeter will be 44 times the side aa.
We will multiply the side of the square by 44.


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Perimeter of the Rectangle

A3 - Perimeter of the rectangle

Let's add up the sides of the rectangle. The opposite sides are equal.

More information about the Perimeter of the rectangle


Perimeter of the triangle

A4 - Perimeter of the triangle

Let's add up all the sides of the triangle.
In an isosceles triangle it is enough to know the length of the base and one of the two equal sides.
In an equilateral triangle it is enough to know the length of one side.

More information about the Perimeter of the triangle


Do you know what the answer is?

Perimeter of a Rhombus

A5 - Perimeter of the rhombus

aa -> side of the rhombus
In the rhombus all sides are equal, therefore, its perimeter will be 4 times the side a.


Perimeter of a Parallelogram

A6 - Perimeter of a parallelogram

Let's add up the sides of the parallelogram. The opposite sides are equal.

More information about the Perimeter of a parallelogram


Check your understanding

Circle Perimeter

B7 - Circumference perimeter

rr –>  Radius of the circumference
Pi ππ will be calculated as the number –> 3.14 3.14 

Let's multiply Pi –> 3.14 3.14  by the radius by 22

More information about the Circle's perimeter


Perimeter of the Trapezoid

Do you think you will be able to solve it?

Perimeter of the deltoid

A9  - Perimeter of the deltoid

In the deltoid, the 2 adjacent sides are equal.


Perimeter of Composite Figures

The key to calculating the perimeter of these figures is to add up absolutely all the sides without forgetting any of them.
Start on one side, follow the entire round and stop when you reach the same side from which you started.

Let's see an example:

Perimeter of composite figures

The area is:
4+4+4+5+2+8+2+3=324+4+4+5+2+8+2+3=32


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What is the difference between perimeter and surface area?

The perimeter is measured in two-dimensional figures that do not have volume, for example, a rectangle

The perimeter in two-dimensional figures

In contrast, the surface area is measured in three-dimensional figures that do have volume, for example, a cylinder or cube.


Examples and exercises with solutions for the perimeter of the parallelogram

Exercise #1

Calculate the perimeter of the parallelogram ABCD.

CD is parallel to AB.

777121212AAABBBCCCDDD

Video Solution

Step-by-Step Solution

Let's recall the properties of parallelograms, where pairs of opposite sides are parallel and equal.

Therefore, AB is parallel to CD

Therefore, BC is parallel to AD

From this, we can conclude that AB=CD=7

And also BC=AD=12

Now we can calculate the perimeter by adding all the sides together:

7+7+12+12=14+24=38 7+7+12+12=14+24=38

Answer

38

Exercise #2

Given the triangle:

777111111131313

What is its perimeter?

Video Solution

Step-by-Step Solution

The perimeter of a triangle is equal to the sum of all its sides together:

11+7+13=11+20=31 11+7+13=11+20=31

Answer

31

Examples and exercises with solutions for the perimeter of a trapezoid

Exercise #1

Calculate the perimeter of the parallelogram ABCD.

CD is parallel to AB.

777121212AAABBBCCCDDD

Video Solution

Step-by-Step Solution

Let's recall the properties of parallelograms, where pairs of opposite sides are parallel and equal.

Therefore, AB is parallel to CD

Therefore, BC is parallel to AD

From this, we can conclude that AB=CD=7

And also BC=AD=12

Now we can calculate the perimeter by adding all the sides together:

7+7+12+12=14+24=38 7+7+12+12=14+24=38

Answer

38

Exercise #2

Given the triangle:

777111111131313

What is its perimeter?

Video Solution

Step-by-Step Solution

The perimeter of a triangle is equal to the sum of all its sides together:

11+7+13=11+20=31 11+7+13=11+20=31

Answer

31

Examples and exercises with solutions for the perimeter of the triangle

Exercise #1

Calculate the perimeter of the parallelogram ABCD.

CD is parallel to AB.

777121212AAABBBCCCDDD

Video Solution

Step-by-Step Solution

Let's recall the properties of parallelograms, where pairs of opposite sides are parallel and equal.

Therefore, AB is parallel to CD

Therefore, BC is parallel to AD

From this, we can conclude that AB=CD=7

And also BC=AD=12

Now we can calculate the perimeter by adding all the sides together:

7+7+12+12=14+24=38 7+7+12+12=14+24=38

Answer

38

Exercise #2

Given the triangle:

777111111131313

What is its perimeter?

Video Solution

Step-by-Step Solution

The perimeter of a triangle is equal to the sum of all its sides together:

11+7+13=11+20=31 11+7+13=11+20=31

Answer

31

Examples and exercises with solutions for the perimeter of the rectangle

Exercise #1

Calculate the perimeter of the parallelogram ABCD.

CD is parallel to AB.

777121212AAABBBCCCDDD

Video Solution

Step-by-Step Solution

Let's recall the properties of parallelograms, where pairs of opposite sides are parallel and equal.

Therefore, AB is parallel to CD

Therefore, BC is parallel to AD

From this, we can conclude that AB=CD=7

And also BC=AD=12

Now we can calculate the perimeter by adding all the sides together:

7+7+12+12=14+24=38 7+7+12+12=14+24=38

Answer

38

Exercise #2

Given the triangle:

777111111131313

What is its perimeter?

Video Solution

Step-by-Step Solution

The perimeter of a triangle is equal to the sum of all its sides together:

11+7+13=11+20=31 11+7+13=11+20=31

Answer

31

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