Originally Posted by
stapel Study the information (such as the links) provided
in this thread.
Then please reply specifying where you are getting stuck on this exercise.
Thank you!
Hey Staple I was hoping if you would just verify what Andy was asking you
in that thread in the 6th post(The last post)...Was he correct in his
answer?
andyboy179
scale factor
hi, i posted a question a little while ago and it was like this, what are dimensions of an A3 piece of paper is when the A4 piece of paper has been enlarged by scale factor of 2. i got the answer which is 59.4 X 84 cm.
my question today i like that one so here it is, what is the scale factor of enlargement of an A4 piece of paper >A5 piece and A3 piece >A5 piece.
if anyone can help please post thanks
First of all make sure that
 you know that you are dealing with standard dimension.
 The above point means that An has a fixed size for every n
 example: A4 will always have dimension 210 x 297 mm
 210 mm will be breadth 297 will be length of paper
Code:
Observe this table(mm)
A0 841 × 1189
A1 594 × 841
A2 420 × 594
A3 297 × 420
A4 210 × 297
A5 148 × 210
A6 105 × 148
A7 74 × 105
A8 52 × 74
A9 37 × 52
A10 26 × 37
You will observe from the above that
 $\displaystyle Breadth~ of ~A_{n+1} = Length ~of~ A_{n} $
Now what ISO thought while making A size papers
the area of A0 must be 1 m^2
it should be a rectangular paper
so they selected a factor $\displaystyle \sqrt{2}$ between length and breadth
So if we consider breadth as a , the length will be $\displaystyle = a\sqrt{2} $
for A0 computing with area
$\displaystyle a^2 \sqrt{2} = 1m^2 $
$\displaystyle a^2 = \frac{1}{\sqrt{2}} $
$\displaystyle
a= \frac{1}{^4\sqrt{2}}$
$\displaystyle a \approx 841mm $
Thus the breadth of A0 = 841 mm , its $\displaystyle length = 841\sqrt{2} $

Now for A1
Its $\displaystyle breadth = Breadth ~of ~A_0/\sqrt{2}$
Its $\displaystyle length = Length~ of ~A_0 /\sqrt{2}$ ........(this is equal to breadth of A0)

Thus for any $\displaystyle A_{n+1}$
$\displaystyle Length = \frac{Length ~of ~A_{n}}{\sqrt{2}}$
$\displaystyle Breadth = \frac{Breadth ~of ~A_{n}}{\sqrt{2}} $
Hence the scale factor for respective dimensions of successive members of A series(Like A0 and A1) is $\displaystyle \sqrt{2}$
Similarly scale factor for A0 and A2 is $\displaystyle \sqrt{2}^2 = 2 $ ie: both length and breadth differ by a factor of 2
For A3 to A5 scale factor is 2
for A3 to A6 $\displaystyle 2 \sqrt 2$
your first question wanted you to hypothetically enlarge every size by scale factor 2 all you did was to find new length and breadth if every thing gets hypothetically enlarged by scale factor 2.

Adarsh