Naming a Polygon and Its Parts | Matatag Curriculum | Grade 7 | Explain in Detailed |

Summary

In this educational video, Teacher MJ introduces the concept of polygons, focusing on naming and identifying their parts. The lesson defines a polygon as a closed figure with line segments in a two-dimensional plane. It distinguishes between a triangle, with three sides, and a quadrilateral, with four sides. The video explains the components of a polygon, including vertices where sides meet, sides as line segments, and angles formed by these sides. Teacher MJ emphasizes the importance of using consecutive vertices when naming polygons, providing multiple examples and variations for both triangles and quadrilaterals, ensuring a comprehensive understanding of the topic.

Takeaways

• 📚 A polygon is a closed figure made up of line segments in a two-dimensional plane.
• 🔢 A polygon with three sides is called a triangle, and one with four sides is called a quadrilateral.
• 📐 The parts of a polygon include vertices (points where sides meet), sides (line segments), and angles.
• 📌 The vertex is the point where two sides or line segments of a polygon meet, forming a corner.
• 🌐 Sides of a polygon are the line segments that connect the vertices, and they can be named in any order but are usually listed alphabetically.
• 🔄 Angles in a polygon are formed by two adjacent sides and can be named based on the vertices that form them, ensuring the vertex names are in a clockwise or counterclockwise order.
• 📝 When naming a polygon, the vertices must be listed consecutively, and the names must reflect this order.
• 🔄 For a triangle, there are six possible namings based on the order of the vertices, while a quadrilateral has eight possible namings.
• 📐 In a quadrilateral, the sides are named as pairs of vertices they connect, such as AB, BC, CD, and DA, and can be read in either direction.
• 📝 The script emphasizes the importance of consecutive vertex naming for polygons and provides examples of correct and incorrect naming conventions.
• 🤓 The lesson encourages students to ask questions and engage with the material, promoting an interactive learning environment.

Q & A

What is a polygon?

A polygon is a closed figure made up of line segments in a two-dimensional plane.

What is the term for a polygon with three sides?

A polygon with three sides is called a triangle.

What is the term for a polygon with four sides?

A polygon with four sides is called a quadrilateral.

What is a vertex in the context of a polygon?

A vertex is a point on a polygon where two line segments meet.

How many vertices does a triangle have?

A triangle has three vertices.

How many sides does a quadrilateral have?

A quadrilateral has four sides.

What is the term used for the line segments that form the perimeter of a polygon?

The line segments that form the perimeter of a polygon are called sides.

How are the sides of a polygon named?

The sides of a polygon are named by the vertices they connect, such as side AB or line segment AB.

What is an angle in a polygon?

An angle in a polygon is the figure formed by two sides or line segments meeting at a vertex.

How can you name a triangle using its vertices?

A triangle can be named using any three consecutive vertices, such as triangle ABC.

What is the rule for naming a quadrilateral using its vertices?

A quadrilateral should be named using consecutive vertices, such as quadrilateral ABCD.

Can the vertices of a polygon be named in any order?

No, when naming a polygon, the vertices must be listed in a consecutive order.

What is the difference between a line segment and a side in a polygon?

A line segment is a part of a polygon that connects two vertices, while a side refers to the entire length between two vertices, forming part of the polygon's perimeter.

How many names can a triangle have based on its vertices?

A triangle can have six different names based on its vertices, such as triangle ABC, triangle BCA, triangle CAB, triangle BAC, triangle ACB, and triangle CBA.

How many names can a quadrilateral have based on its vertices?

A quadrilateral can have eight different names based on its vertices, such as quadrilateral ABCD, quadrilateral ABDC, quadrilateral ACBD, quadrilateral ACDB, quadrilateral BACD, quadrilateral BADC, quadrilateral BCDA, and quadrilateral BDAC.

Outlines

00:00

📚 Introduction to Polygons and Their Parts

This paragraph introduces the topic of the video, which is about naming polygons and understanding their parts. The instructor, Teacher MJ, defines a polygon as a closed figure in a two-dimensional plane formed by line segments. It explains the basic types of polygons, such as a triangle with three sides and a quadrilateral with four sides. The paragraph also begins to explore the components of a polygon, starting with the 'vertex,' which is the point where the sides meet. The class is encouraged to identify vertices in a triangle and to understand the concept of vertices in polygons.

05:01

📐 Understanding Polygon Sides and Angles

Building on the concept of vertices, this paragraph delves into the sides of polygons, which are the line segments connecting vertices. The instructor clarifies that sides can be named in any order but are typically listed alphabetically. The paragraph then moves on to discuss the angles within a polygon, which are formed by the intersection of two sides. The class is guided through identifying the angles in a triangle, using the vertices as reference points to name each angle appropriately.

10:04

🔍 Deep Dive into Polygon Angles and Naming Conventions

This paragraph continues the exploration of polygon geometry by focusing on the angles within polygons. It emphasizes the importance of using the central vertex to correctly name the angles, ensuring that the vertices are listed in a consecutive manner. The paragraph also revisits the concept of naming polygons, highlighting the need for consecutive vertices in the naming process. The class is encouraged to practice identifying and naming the different angles of a polygon, ensuring they understand the correct naming conventions.

15:07

📘 Naming Polygons: Quadrilaterals and Beyond

The instructor transitions from triangles to quadrilaterals, discussing the vertices, sides, and angles of a four-sided polygon. The paragraph explains how to name a quadrilateral by using consecutive vertices, with a focus on maintaining the correct order. The class is taught that while there are multiple ways to name a quadrilateral, the vertices must always be listed consecutively. The paragraph also provides examples of incorrect naming to illustrate the importance of consecutive ordering.

20:09

🎓 Polygon Naming Variations and Conclusion

In the final paragraph, the instructor summarizes the process of naming polygons, emphasizing the flexibility in choosing different but correct names as long as the vertices are listed consecutively. The paragraph provides several examples of how a quadrilateral can be named, showcasing the eight different naming variations that are possible. The instructor wraps up the lesson by encouraging the class to ask questions if they have any and reminds them of the importance of practicing and understanding the concepts taught. The video concludes with a reminder to like, share, and subscribe for more educational content.

Keywords

💡Polygon

A polygon is a closed figure in a two-dimensional plane, defined by a finite number of straight line segments connected to form a closed chain. In the video, polygons are the main subject, with the focus on naming and identifying their parts, such as vertices, sides, and angles.

💡Vertex

A vertex is a point where two or more lines meet, specifically in the context of polygons, it is where the sides or line segments of the polygon intersect. The script mentions vertices as fundamental parts of polygons, with examples given for a triangle and a quadrilateral, each having a specific number of vertices.

💡Side

In geometry, a side of a polygon refers to a line segment that connects two vertices. The script explains that sides are parts of polygons and provides examples of sides in a triangle and a quadrilateral, such as side AB or line segment AB.

💡Angle

An angle in the context of polygons is formed by two sides meeting at a vertex. The script discusses angles as an integral part of polygons, with the teacher explaining how to name angles in a triangle, using vertices as a reference, such as angle A or angle CAB.

💡Triangle

A triangle is a specific type of polygon with three sides and three vertices. The video uses the triangle as an example to teach how to identify vertices, sides, and angles, as well as how to name the polygon using its vertices, like triangle ABC.

💡Quadrilateral

A quadrilateral is a polygon with four sides and four vertices. The script explains how to identify the parts of a quadrilateral and how to name it using consecutive vertices, such as quadrilateral ABCD or ADCB, emphasizing the importance of consecutive ordering.

💡Naming Polygons

The process of naming polygons involves using the vertices to identify and label the shape. The script provides a detailed explanation of how to name triangles and quadrilaterals by listing their vertices in consecutive order, such as triangle ABC or quadrilateral ABCD.

💡Consecutive Vertices

When naming polygons, the term 'consecutive vertices' refers to the order in which the vertices are listed, ensuring that they follow the shape's perimeter in a continuous sequence. The script highlights this concept as crucial for correctly naming polygons, as seen when discussing quadrilaterals.

💡Line Segment

A line segment is a part of a line that is bounded by two distinct end points, and in the context of polygons, it represents the sides. The script uses the term to describe the sides of polygons, such as line segment AB in a triangle.

💡Closed Figure

A closed figure is a shape that is formed by a continuous path that starts and ends at the same point, not leaving any gaps. The script defines a polygon as a closed figure made up of line segments, emphasizing that the sides form a complete loop.

💡Two-Dimensional Plane

A two-dimensional plane refers to a flat, level surface that extends infinitely in all directions and has only length and width. The script mentions that a polygon is a closed figure on a two-dimensional plane, indicating that polygons exist in a flat space without depth.

Highlights

Introduction to the topic of naming polygons and their parts.

Definition of a polygon as a closed figure made up of line segments in a two-dimensional plane.

Explanation of a triangle as a polygon with three sides.

Identification of a quadrilateral as a polygon with four sides.

Introduction to the parts of a polygon: vertices, sides, and angles.

Description of a vertex as a point where line segments meet.

Illustration of how to identify vertices in a triangle and a quadrilateral.

Explanation of sides in a polygon as line segments between vertices.

Clarification that sides can be named in any order, but usually listed alphabetically.

Introduction to angles in a polygon as the space between two sides.

Method of naming angles based on the vertices they are formed by.

Rule for naming polygons using consecutive vertices.

Example of naming a triangle with six possible names using consecutive vertices.

Process of naming a quadrilateral with eight possible names, ensuring vertices are consecutive.

Emphasis on the importance of consecutive vertices in naming polygons.

Invitation for students to ask questions and engage with the content.

Conclusion summarizing the lesson on naming polygons and their parts.

Encouragement for students to like, share, and subscribe for more educational content.

Transcripts

Hi guys good day It's me teacher MJ our

topic for today Class is all about

naming a polygon and its parts so

without further ad let's do this topic

now before we name the polygon class and

Identifying its parts let's define first

What is a polygon now polygon is a close

figure made up of line segments in a two

dimensional plane so for this first

illustration class we can call this one

polygon because it is a close figure and

it's made up of line segment

same with number two It is a close

figure made up of line segments now for

number one class we call this one

triangle a polygon with three sides we

call that one triangle and for number

two a polygon with four sides this

remember class What do you call a

polygon with four sides that's correct a

polygon with four sides we call that one

quadrilateral now before we name this

polygon class let's identify first what

are the parts of a polygon so the first

part of a polygon CL we have what we

call the

vertex All right Let's start with the

vertex now Sir what is a vertex now

vertex Class is a point on a polygon

where the sides and the line segments

meet so If This side together with This

side meet we can form a point and this

point right here Class is what we call

the vertex same with this one This side

together with This side when they meet

they can form a point and this point is

what we call the vertex so in this

triangle class we have three vertices

once again singular for this point we

can call this one vertex a so we have

vertex a we have vertex

B We also have vertex

C All right so once again class vertex

two sides or Line segments Meet And they

form a point This is what we call the

vertex in plural form class we can call

this one vertices so we have the

following vertices we have a we have b

and

C now the second part class of a polygon

is what we call the sides All right so

we have the sides now in this given

triangle class we have three sides we

have side ab side BC side AC or we can

also call this one line segment ab line

segment bc and line segment AC once

again we can do this marking for line

segment we have line segment

ab All right and then line segment

bc and then line segment AC So this

marking class horizontal line is what we

called line segment now question sir for

the side ab Okay this line segment ab

can we write This one Sir line segment

ba can we do that one Sir line segment

ba is it the same sir if we write line

segment pa Yep CL that's actually the

same you can read this one line segment

ab or line segment ba but most of the

books class they arrange the letters

alphabetically a comes first before b in

alphabet That's why we have line segment

ab but you can Actually write that one

class line segment ba this is just the

same class All right so let's have

or so we have the first side ab or once

again you can read that one line segment

ba second side BC line segment bc or

line segment CB So this is just the same

class It's up to you which do you prefer

next we have line segment AC or line

segment

ca so let's just write or Okay so It's

up to you which do you prefer you can

choose the sides or the sides so we have

three sides and last one class the part

of a polygon we have what we call the

angles so we have the

vertex we have the sides Okay first part

we have the vertex second part we have

the sides and last one we have what we

call the angles okay last one we have

what we called

angles now in this given triangle class

we have three angles so These are the

following

angles All right this one and this one

so let's start with this one one class

this first angle now this first angle

class we can call this one angle A okay

once again this is the symbol class for

angle we can call that one angle a now

question sir can we call this one angle

C ab can we call that one Sir angle Cab

Yup we can call that one class angle

angle

Cab

Cab just make sure CL that this vertex a

will be the center part of this

following vertices once again just make

sure that this vertex a will be the

center part of this following vertices

angle

Cab sir question can we read this one

angle B AC Yup you can Actually read at

one class angle bac This is this three

Class is just the same either of this

three class that you will choose for

your answer angle bac once again class

mak sure that this vertex a will be the

center part of this following vertices B

AC So that's the first angle right here

class Okay First angle we have angle a

or we can call that one angle Cab next

angle

bac All right though second angle we

have this given angle so let's start

with this given angle second angle angle

B so we can read this one angle B or

right so angle B so second angle angle B

sir can we read this one angle a bc Yup

you can read it one angle

ABC so angle

A B C just make sure class once again

just make sure that this B vertex V will

be the center part of this following

vertices A B C so B will be the center

part of this following three vertices

and you can also read this one cba once

again B should be the center part

cba angle cba so It's up to you class

which do you choose you can have this

answer angle a alone Yep that's okay

angle B alone that's okay or you can

choose this one angle Cab that's okay so

you can choose either of this one class

for this following three angles so you

can just simply use this one and simply

use this one so It's up to you class

which do you prefer So this is just the

same class either of this three class

you can Choose one and last angle we

have this

one angle C All right so we have angle

C so angle C and we can call this one

angle a CB angle a just make sure once

again C will be the center part of this

following vert vertices C Ah sorry AC CB

acb and then

bca angle bca

that's it you're all set for the parts

of a polygon we have the

vertex we have the sides and we have the

angles so the vertices the sides and the

angles so we have the

vertices so let me just box it in red we

have the vertices we have the sides and

we have the

angles now question How will you name

this polygon Sir now to name this

polygon class we can write the word

triangle itself so you can write the

word triangle

itself

triangle then you can read this one a bc

once again CL in naming the polygon It

must be consecutive vertices you can

name this one triangle ABC check plus

the vertices

ABC it is consecutive so triangle

ABC or you can just simply illustrate

this given word angle you can just

simply illustrate this one triangle this

illustration CL it means triangle then

ABC so That's How You name class

question sir question can we read this

one triangle bca is this consecutive

vertices Yep you can read this one class

triangle bca triangle B ca just make

sure class are is consecutive vertices

you read this one consecutive vertices

what else class can we read this one

triangle Cab can we do that one triangle

Cab Yup we can read that one triangle

Okay triangle Cab

Cab All right So what else C can we read

this one triangle a CB can we do that

one so check Do we have it here triangle

acb Yep we can read that one triangle

acb

a CB Let's have counterclockwise

a

CB All Right what else class can we read

this one cba can we do that one Do we

have cba here Yup we can read that one c

b a what else class can we read this one

b a Yup we can read that one b triangle

B

AC All right so That's How You name the

triangles class we have six names for

this one triangle ABC so we have this

one triangle

ABC Al right triangle ABC or we can

write this one this given illustration

right here this marking is what we call

triangle this illustration is a triangle

so we have triangle ABC we have triangle

bca Okay this one 1 2 3 4 5 6 so we can

name this one CL this triangle six names

so we can read this one triangle

ABC triangle BC ca so once again CL as

long as the as long as the vertices you

read that one cons with consecutive

vertices but once again class mostly in

the books class they arrange the letters

alphabetically That's why you have

triangle ABC Okay triangle

ABC All right so let's have example

number two so I hope you get this one CL

for example number one if you have some

questions CL do not hesitate to ask CL

once again do not hesitate to ask if you

have some question with number one CL

feel free to ask us you put your comment

in the com section down below All right

Let's have example number two All right

so let's have example number two once

again we start at the

vertex so the vertex we have Okay vertex

we have vertex a so we have vertex

a right and then we have vertex B so we

have four vertices vert b and then vert

C All right and then vertex

d or we can write this one we have the

following vertices so the vertices We

have

a we have B we have C and we have d so

we have four vertices All right We're

done with the vertices for number

two All right so next step or the next

part of a polygon we have what we call

the

sides so next we have the

sides All right so we have side ab once

again side ab so or we can write this

one line segment ab or we Just write or

class for you to choose which do you

prefer so we have side ab or we can read

it one line segment ba we have line

segment ab or line segment ba that's

Actually the same All right and we have

line segment

bc or we can write that one CB line

segment CB So that's Actually Okay class

CB line segment CD so line segment CD or

we have DC line segment DC and then line

segment

ad or we have line segment

da All right so Just write or class once

again class It's either of this two

class you can choose line segment ba

that's Actually Okay you can choose line

segment CB for bc instead of bc you can

choose CB okay or you can just simply

use this following sides ab side ab line

segment ab line segment bc line segment

CD and then line segment

ad All right So we're done with the

sides now next step we have the

following

angles so angles

So we're done with the

vertices So we're done with the

vertices We're done with the sides and

next will be the angles so we have Let's

start with the angle a Okay so angle

a so angle a now we can call this angle

a so once again this is the first angle

we have angle a Now you can also read

this one class angle b a angle b

a or we can read that one angle

daab angle d ab once again class just

make sure Okay just make sure class that

this vertex A okay this vertex a will be

the center part of this following

vertices make sure that this vertex a

will be the center part of this

following vertices so bad or

dab All right and We also have this

given angle angle

B so we can read this one angle

B All right so angle b and then angle

ABC so angle a bc or that would be angle

cba angle C then B then a once again

just make sure that this B will be the

center part of this following three

vertices so ABC this given angle or

cba All right So we're done with the

second angle Let's have the third angle

So this given angle right here angle C

so we can read that one angle

C All right so angle C or we can read

this one angle

bcd angle bcd

bcd or angle dcb angle d C then B so we

don't have enough space class angle

d c then

B All right and then last one so we have

vertex

a CD we have the sides four sides we

have four vertices and we have four

angles one two three and then last one

this one angle

d so we have angle d or we can read this

one angle d that would be angle a DC

angle a then d then

C or angle

cda

cda once again Let's make sure that this

d will be the center part of this

following vertices cda angle CD then a

All right so All set class for the

vertex for the sides and the angle so

next step class we name this

quadrilateral so be careful class in

naming this quadrilateral once again

class always remember it must be

consecutive vertices All right So this

one class so quadrilateral You can put

the word itself

quadrilateral

quadrilateral All right so

quadrilateral a b cd a b c d so once

again Let's make sure that the vertices

are consecutive vertices a b c d

question sir can we read this one once

again once again CL for this

quadrilateral class you can just simply

write the symbol or draw the symbol

class it means quadrilateral So this is

the symbol of Quadrilateral class this

is the symbol so you can just simply

write this one or draw the symbol and

then a CD that's Actually Okay class it

means quadrilateral ABC d once again the

symbol right here it means quadrilateral

then ab CD So you Pause the video class

because we will be naming this one Okay

we will be naming this one you Pause the

video I'll be erasing this one class we

don't have enough space because we need

to name this one class is step by step

Okay so you Pause the video I'll be

erasing this one and then we will be

naming the quadrilateral sir can we name

this one

quadrilateral

acbd How about this one one class AC bd

can we do that one class can we name

that one quadrilateral AC C bd can we do

that one Nope we cannot do that one

class Okay we cannot do this one Why is

that sir Because the vertices class are

not consecutive it is opposite to C

class A is opposite to C we cannot do

that one class it should be consecutive

vertices question sir can we read this

one

quadrilateral

adcb can we do that one Sir a d CB a CB

can we do that one Sir Yup you can

Actually do that one class this is

acceptable class we can read this one AC

DB a i sorry

adcb a d CB because the vertices class

are consecutive a next is D next is c

next is B so we can name that one A D CB

what else CL so we can name this one

Quad trilateral d cba Yup we can do that

one D

cba Okay can we name this one class c a

DB can we do that one class c a DB can

we do that one Nope we cannot do that

one because once again quadrilateral

ca DB can we do that one c a DB Nope we

cannot do that one class because c is

opposite to a It must be consecutive

class so we cannot do this one So it

should be

quadrilateral Okay

quadrilateral CB a c b a d All right So

what else class so we cannot do this one

this is opposite the vertices are

opposite what else class so Help me with

this one class we have

CB a d so we can read this one a b an

Sorry b a DC b

a

DC All right So what else class we have

b a DC then ad CB We're done with this

one Okay let's have clockwise so a CD ab

CD and then bc Do we have bcda nope

don't have it here All right so

quadrilateral bcda

bcda and then quadrilateral

cdb

CD ab and then

quadrilateral DC Do we have DC Nope we

don't have d a b Den da B denc that's it

CL all set so we have how many names CL

1 2 3 4 5 6 7 8 so we can name this one

eight Okay we can name this one It

depends on nucleus which to prefer class

so we can name this one class

quadrilateral

ABCD

ABCD

adcb so we can do that one class As Long

class just remember this one class you

can name any polygon As long the

vertices are consecutive vertices class

one after another so a b c d b c d a you

can do that one c d a b All right so

That's How You name class you can choose

class either of this one class you can

have this answer you can have this one

either of this one this one this one so

just Choose one class so let's have this

one class but once again class It's up

to you which do you prefer you can

Choose any of this one class you can

Choose one All right so I hope you learn

something new today class that's it for

naming a polygon and it's part so I hope

you learn something new today once again

if you have some questions with regards

to this one CL do not hesitate to ask

you put your question comment section

down below so I hope you learn something

new today class Do not forget to like

share and subscribe you share to your

friends and to your classmates so that

we can help more students once again

this is teacher MJ Have a great day

class Goodbye for now Byebye