Need up to 30 seconds to load.

- [Instructor] So right over here,

Figure B is a scaled copy of Figure A

and what we wanna do is figure out

what is the scale factor to go from Figure A to Figure B?

Pause the video and see if you can figure that out.

Well, all we have to do is look at corresponding sides

and think about how much they have been scaled by.

So for example, this side right over here

would correspond to this side right over here on Figure B

and over here, it had length two

and over here, it has length

one, two, three, four, five, six.

So it looks like that side has been scaled up

by a factor of three

and so if Figure B truly is a scaled copy

then every side should be scaled up by a factor of three

and we could verify that.

We don't have to do it with every side.

We're being told that these are scaled copies

but we can see that this is the case.

For example, this side right over here

corresponds to this base right over here.

This has length three.

So if we're scaling up by a factor of three,

we should multiply that by three

and this should be of length nine.

Let's see if that's the case.

One, two, three, four, five, six, seven, eight and nine.

And so you can see we can feel pretty good

that Figure B is a scaled copy of Figure A

and that scaling factor is three.

Let's do another example.

So here, we are told Ismael made a scaled copy

of the following quadrilateral.

He used a scale factor less than one, alright,

and then they say what could be the length

of the side that corresponds to AD?

So AD is right over here.

AD has length 16 units in our original quadrilateral.

What could be the length

of the side that corresponds with AD

on the scaled copy of the quadrilateral?

So it's a scale factor less than one.

So we're gonna get something that is less than 16

for that side

and the rest of it will all be scaled by the same factor.

So the resulting quadrilateral might look something,

might look something like this.

This is just my hand-drawn version.

So the key realization is

is if our scale factor is less than one,

this thing right over here

is going to be less than 16 units.

So let's look at the choices

and it says choose three answers.

So pause the video and which of these would match

if we're scaling by a factor of less than one?

Well, we just have to see which of these

are less than 16 units.

This is less than 16.

This is less than 16.

This is less than 16

and those are the only three that are less than 16.

32 units, this would be a scale factor of two.

64 units, this would be a scale factor of four.

Clearly a scale factor that is not less than one.