Question

Feedback.

Answer 1

Sorry @OOOPS your helping me a lot

Answer 2

nope for the first one

Answer 3

Okay... and the rest?

Answer 4

Let's tag others. I am sorry, I am quite tired, dare not to give you what I don't think carefully. @ganeshie8

Answer 5

okay thank you!

Answer 6

@jim_thompson5910

Answer 7

okay how about the rest.

Answer 8

OKay thank you.

Answer 9

is 22 going to be 27:8

Answer 10

@jim_thompson5910

Answer 11

There is an relation between "scaled" figures (the same shape, but one is an enlarged version of the other)

this rule works for any shape.

if you make all the sides 3 times bigger, the area (or surface area) goes up by the square. in other words 3^2

and the volume goes up by the cube, 3^3

Answer 12

which question are we discussing

Answer 13

For question 22, you have a *length* (the radius) that is changed from 6 to 4
the cylinders are similar, so that means that if we changed the radius, *everything* else was shrunk in the same way.

now we use the rule:
the surface area changes by the square of 6/4
the volume changes by the cube of 6/4

Answer 14

you should first simplify 6/4 by dividing top and bottom by 2 to get 3/2

that is the ratio of *lengths* (e.g. the radius, or the height)
the ratio of their surface areas will be (3/2)^2 or (3/2)*(3/2)
the ratio of their volumes will be (3/2)^3 or (3/2)*(3/2)*(3/2)

Answer 15

For Q23, they give you a scale factor of two similar figures as 2:5 (this applies to the length of the figure)
this immediately tells you the ratio of their surface areas: (2/5)^2
and the ratio of their volumes: (2/5)^3

Answer 16

can you answer the first question?

Answer 17

I think that is is 27:8 but Im not quite sure

Answer 18

the ratio of their volumes will be (3/2)^3 or (3/2)*(3/2)*(3/2)

Answer 19

so therefore I am right!

Answer 20

Because when you multiply 3*3*3 you get 27
and when you multiply 2*2*2 you get 8 I don't think that you can simplify that.

Answer 21

if you multiply 3/2 * 3/2 * 3/2 you get 27/8

You start with: ratio of similar figures is 6/4 = 3/2 (and this is a ratio of *lengths*)
now you know the ratio of their surface areas is (3/2)^2
and volumes (3/2)^3

Answer 22

ok, that was the first question.

Can you try Q23?

Answer 23

yes, 23 so what you to do is do 2/5*2/5*2/5

Answer 24

in Q23 it is asking about *area* (not volume)

Answer 25

only twice*

Answer 26

yeah sorry, 2/5*2/5

Answer 27

yes 2/5 * 2/5 = (2*2)/ (5*5)

Answer 28

which equals 4/25

Answer 29

so it would be false?

Answer 30

yes, it's false

Answer 31

yeah! And I don't get 24

Answer 32

scale factor 1:12 (which means lengths)
example: toy train is 1 ft long, real train is 12 feet long.

what is the ratio for *area* ?

Answer 33

Square it

Answer 34

yes, what do you get?
you have 1/12 for lengths
what is it for area ?

Answer 35

It would be 1:24

Answer 36

the ratio for areas is (1/12)*(1/12)
multiply top times top and bottom times bottom
1/144
( FYI and for volumes the ratio is 1/1728 )

Answer 37

oh okay sorry

Answer 38

1/24 is 1/12 * ½ which is not correct

Answer 39

now that you have the ratio of surface areas we use it in an equation of ratios

Answer 40

yeah I did a math error your suppose to do 12*12 not 12*2

Answer 41

the ratio 1/144 is model's area/actual area
we set that equal to the model's area/ x unknown actual area

Answer 42

so would it be