the vertex of an angle is the point where the rays or line segments meet.

why is B used more than A in these questions?

I'm not sure. thank you for making me notice that

At 11:00 how do I practice to get better at noticing angles, can khan academy help me with that

A place where two rays meet is called an angle.

why are angels measured in degress

the babylonians (an ancient civilization, like Greeks) invented the 360 degree value which is the maximum an angle can be (which is a complete circle and after that, it kinda repeats on itself and the value of the angle gets even bigger). It's based on their base 60 counting (/number) system. There also exist other ways like radian ( angles are measured in pi) and tau (basically, "2*radians" tau = 2pi.)

why are you not showing if it is a right angle or something like that?

Because you need to figure it out yourself

how do you measure an angle

ABC angle would measure how far A to C is

I did not know it my teacher did not Teach me this.

Maybe you were out someday when she taught it. Anyway, Right angle=90 degrees, Obtuse angle=more than 90, acute angle=less than 90.

Main content

Angle basics review

CCSS.Math:

4.MD.C.5

Google Classroom

Review what an angle is and how an angle is measured.

What is an angle?

An angle is two rays that share a start color #11accd, start text, v, e, r, t, e, x, end text, end color #11accd.

Intersecting lines or line segments also form angles.

Practice: Identifying an angle

Problem 1

Which of the following figures is an angle?

Measuring angles

Angles are measured in degrees.

The wider an angle is open, the greater its measure. If you compare these two angles, the first one is open wider.

So, the measure of this angle

is greater than the measure of this angle.

Practice set: Which angle is greater?

Problem 2A

Current

Which angle measure is greater?

Want to try more problems like this? Check out this exercise.

Want to join the conversation?

Sort by:

Dawson Allen
Posted 5 years ago. Direct link to Dawson Allen's post “What is a Vertex?”
What is a Vertex?
Button navigates to signup pageComment on Dawson Allen's post “What is a Vertex?”
(65 votes)
Answer
- Tom Marvolo Riddle
  Posted 5 years ago. Direct link to Tom Marvolo Riddle's post “the vertex of an angle is...”
  the vertex of an angle is the point where the rays or line segments meet.
  Comment on Tom Marvolo Riddle's post “the vertex of an angle is...”
  (113 votes)
JacobthePlayer
Posted 5 years ago. Direct link to JacobthePlayer's post “So, do angles relate to s...”
So, do angles relate to shapes like squares and circles?
Button navigates to signup pageComment on JacobthePlayer's post “So, do angles relate to s...”
(28 votes)
Answer
- alvini
  Posted 4 months ago. Direct link to alvini's post “they do”
  they do
  Comment on alvini's post “they do”
  (9 votes)
20mendozaadrian
Posted 4 years ago. Direct link to 20mendozaadrian's post “At 11:00 how do I practic...”
At
11:00
how do I practice to get better at noticing angles, can khan academy help me with that
Button navigates to signup pageComment on 20mendozaadrian's post “At 11:00 how do I practic...”
(18 votes)
Answer
- jaiswaljulie25
  Posted 6 months ago. Direct link to jaiswaljulie25's post “A place where two rays me...”
  A place where two rays meet is called an angle.
  Comment on jaiswaljulie25's post “A place where two rays me...”
  (8 votes)
caylee.kohn
Posted a year ago. Direct link to caylee.kohn's post “why is B used more than A...”
why is B used more than A in these questions?
Button navigates to signup pageComment on caylee.kohn's post “why is B used more than A...”
(20 votes)
Answer
- 2234014
  Posted 4 months ago. Direct link to 2234014's post “I'm not sure. thank you ...”
  I'm not sure.
  
  thank you for making me notice that
  Button navigates to signup page
  (8 votes)
Nahu Gebre
Posted 2 years ago. Direct link to Nahu Gebre's post “why are angels measured i...”
why are angels measured in degress
Button navigates to signup pageComment on Nahu Gebre's post “why are angels measured i...”
(17 votes)
Answer
- Kshitij
  Posted 2 months ago. Direct link to Kshitij 's post “the babylonians (an ancie...”
  the babylonians (an ancient civilization, like Greeks) invented the 360 degree value which is the maximum an angle can be (which is a complete circle and after that, it kinda repeats on itself and the value of the angle gets even bigger). It's based on their base 60 counting (/number) system. There also exist other ways like radian ( angles are measured in pi) and tau (basically, "2*radians" tau = 2pi.)
  Button navigates to signup page
  (5 votes)
akywi
Posted 5 months ago. Direct link to akywi's post “how do you measure an ang...”
how do you measure an angle
Button navigates to signup pageComment on akywi's post “how do you measure an ang...”
(13 votes)
Answer
- ethan.smidt
  Posted 4 months ago. Direct link to ethan.smidt's post “ABC angle would measure h...”
  ABC angle would measure how far A to C is
  Comment on ethan.smidt's post “ABC angle would measure h...”
  (11 votes)
gjbaboyian
Posted 3 years ago. Direct link to gjbaboyian's post “why are you not showing i...”
why are you not showing if it is a right angle or something like that?
Button navigates to signup pageComment on gjbaboyian's post “why are you not showing i...”
(15 votes)
Answer
- .:Gabriela_Marq:.
  Posted 2 months ago. Direct link to .:Gabriela_Marq:.'s post “Because you need to figur...”
  Because you need to figure it out yourself
  Button navigates to signup page
  (3 votes)
skylar.thomas
Posted a year ago. Direct link to skylar.thomas's post “what is a plane figure”
what is a plane figure
Button navigates to signup pageComment on skylar.thomas's post “what is a plane figure”
(12 votes)
Answer
- 455418
  Posted 4 months ago. Direct link to 455418's post “1000”
  1000
  Comment on 455418's post “1000”
  (8 votes)
jayden
Posted 3 years ago. Direct link to jayden's post “but if the wider angle is...”
but if the wider angle is greater then what is a circle
Button navigates to signup pageComment on jayden's post “but if the wider angle is...”
(13 votes)
Answer
- Alex P
  Posted 3 months ago. Direct link to Alex P's post “360 is a circle’s angle.”
  360 is a circle’s angle.
  Comment on Alex P's post “360 is a circle’s angle.”
  (7 votes)
Adly.G
Posted 8 months ago. Direct link to Adly.G's post “I did not know it my teac...”
I did not know it my teacher did not Teach me this.
Button navigates to signup pageComment on Adly.G's post “I did not know it my teac...”
(11 votes)
Answer
- .:Gabriela_Marq:.
  Posted 2 months ago. Direct link to .:Gabriela_Marq:.'s post “Maybe you were out someda...”
  Maybe you were out someday when she taught it. Anyway, Right angle=90 degrees, Obtuse angle=more than 90, acute angle=less than 90.
  Comment on .:Gabriela_Marq:.'s post “Maybe you were out someda...”
  (5 votes)

4th grade

Course: 4th grade > Unit 11