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## Geometry (all content)

### Course: Geometry (all content)>Unit 2

Lesson 3: Constructing angles

# Constructing angles review

Review constructing angles with a protractor, then try constructing some of your own.

## Constructing angles

We can use a protractor to help us construct an angle of a given amount of degrees.
Example
Construct a 65, degrees angle.
To make a 65, degrees angle, we move the middle dot of the protractor to the vertex (where the 2 rays connect) of the angle.
A protractor shows points plotted at 160 and 180 degrees. Rays go out from a vertex at the protractor's center and through each point.
Next, we line up one of the rays on the 0, degrees line of the protractor.
A protractor shows points plotted at 0 and 180 degrees. Rays go out from a vertex at the protractor's center and through each point.
We then move the other ray around until it is lined up with the 65, degrees measurement on the protractor.
A protractor shows points plotted at 0 and 65 degrees. Rays go out from a vertex at the protractor's center and through each point.
The angle will look like this when the measurement is 65, degrees. Note: The angle can be rotated in any direction, but the angle between the two rays must look like this.
An angle is formed by two rays extending out from a common point. The size of the angle is the same as in the previous image.

## Practice

Problem 1
• Current
Construct a 40, degrees angle.

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

## Want to join the conversation?

• i love angle things. could you make more exercises?
• Of course they would dude!You could donate to make it more convincing though.
• It really makes me feel stupid when I get these questions wrong.
• You have no reason to feel stupid! This can be hard for some people and there is absolutely no shame in asking questions! I am here for you, I know math can be challenging but we have this beautiful community in Khan Academy to support you. Telling people that you don't understand is a very brave thing to do.
• Who thinks we need angles all he time in real life? Vote if yes.Reply if no!
• Angles are absolutely everywhere. For instance take the doornob of a door.How much does it turn? Than Answer shall come as an angle.

So you see, we are all surrounded with angles.Actually Everything around us has geometry or Mathematics in it.
• Super easy angles i mean right?
• Yep!The protractors were a bit glitching at the start.
• This is really easy right? I only *just started* doing angles with protractors and I seemed to know
• This is a great way of learning because the schools are not open. Khan academy is such a great way to learn stuff. It is easy to understand what they are trying to teach
• This is not great for me thou I'm having tons of glitches and some stuff wont respond I'd rather have paper