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Description:

Curious to find out what angle these guys are playing? Check out this video. You’ll have angles coming out of the wazoo.

Language:
English Language

Transcript

00:00

Polygons, a la Shmoop. Farmer Polly at the Circle-P Farm needs to

00:11

build some pens for her exotic animals.

00:15

Polly doesn't want her animals to escape...

00:20

...so she needs to build the animal pens in the shape of polygons.

00:27

So what's a polygon?

00:28

A polygon is any closed figure with three or more straight sides. "Closed" means that

00:34

all sides connect together.

00:37

There are no gaping holes in it that the three-toed sloth could escape through... very... slowly...

00:43

These are not polygons: And no, a circle is not a polygon. It doesn't

00:48

meet all the requirements... don't forget about the straight sides.

00:53

Now these beauties, these are polygons. No animals are getting out of these bad boys.

00:58

The last time the land octopus and the wallabies got out, Polly had a litter of eight-legged

01:02

wallabies to round up.

01:04

Those things can kick like you wouldn't believe. Unless you live in a circular cave, you've

01:08

probably heard of triangles. Well, triangles are polygons with three sides.

01:13

What do you call a polygon with four sides? A quadrilateral....

01:19

Here are some key terms you should know: Angle: the shape formed when two rays meet

01:25

at a common point.

01:29

Vertex: the point where two rays meet; the corner point of a polygon. The plural

01:38

of vertex is vertices....

01:41

Side: the straight edge of a polygon. These are regular polygons...

01:48

...called equilateral and equiangular, which means all sides are equal length and all angles

01:57

are equal in measure.

01:59

Since they're regular, Polly will put all the regular animals in here: the crocodiles,

02:04

the giraffes, the fainting goats....

02:07

Trust us, compared to the rest of these animals, the fainting goats are pretty regular.

02:11

Now these suckers are not regular.

02:14

There could be a few reasons:

02:16

All sides are not equal.

02:18

All angles are not equal.

02:20

All sides and all angles are not equal. Nothing's equal. Not a thing.

02:25

This is where Polly will put those eight-legged kangaroos, the flying sloth, and the talking

02:29

donkey.

02:35

He's such a smart... well, let's just say he has quite a mouth on him.

02:39

Finally, there are convex and concave polygons. A convex polygon has no angles pointing inwards.

02:46

More precisely, no internal angles can be more than a hundred eighty degrees.

02:50

...So basically what the fence looks like when the bull moose gets angry.

02:55

If there are any internal angles greater than a hundred eighty degrees, then the polygon

02:58

is concave. Now you're ready to help Farmer Polly out

03:04

on the farm.

03:05

Don't worry, you won't have to milk the bovine-ocerus until you learn about volume and cylinders...

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