Math 4: All About Angles

Angles are everywhere. In fact, did you know that each of us has our own guardian angle? Guardian angles are constantly watching over us, making sure that none of us cheat on our math homework.

4th GradeMath
Elementary and Middle School4th Grade
LanguageEnglish Language

Transcript

00:24

Houses, cars, and streets would all look different. [Guy walking down a wavy street]

00:27

So maybe it’s time to give angles a little more than a side-long glance.

00:31

…Whoops. [Guy walks into a street sign]

00:32

Sorry.

00:33

We'd like to say that we didn't see that coming, but that'd be a lie…

00:35

…We just thought it'd be funny.

00:37

Anyway!

00:38

Let's take a closer look at angles, with the help of this line! [Line moving around on a piece of paper]

00:42

The first angle you need to know about is an “acute angle.”

00:46

That’s an angle smaller than 90-degrees...

00:48

…and frequently seen with puppies and kittens… [Acute angle next to cats and dogs]

00:50

Aww…how small and cute.

00:53

Next up: the right angle.

00:55

You’re probably familiar with this angle from the meeting of perpendicular lines, or

00:59

the corners of squares.

01:00

A right angle is exactly 90-degrees.

01:03

Our lil' line’s gonna want to be super prepared for our last example.

01:06

That’s because our final angle can be a little hard to get. [Angle studying in a library]

01:10

Why?

01:11

It's obtuse.

01:12

An obtuse angle is an angle that is larger than 90-degrees, but smaller than 180-degrees.

01:16

And those are our three types of angles.

01:19

Thanks for the demonstrations, Line!

01:21

You can find examples of these angles everywhere. [Man walking up the stairs]

01:23

For instance, your stairs are all right angles… [Right angles of the stairs highlighted]

01:26

Well…hopefully.

01:27

Your attic is probably an acute angle.

01:29

Even if nothing in the attic is particularly cute. [Scary looking doll appears]

01:33

And that slice of pizza your little sister grabs for herself? [Hand grabs a big slice of pizza]

01:36

Probably an obtuse angle.

01:38

Yup, angles are everywhere. [Man walks into a room and trips over]

01:39

…sorry.

01:40

We saw it coming again.

01:41

No one ever said we were nice.