So I have this problem... (math problem)

2008-04-28 02:40:16

#1

~Smokey~: Steve Irwin Reincarnate; +396|6576|Internetfitlerland

A maths problem to be exact

If I fold a piece of A4 paper from one corner to another, it makes something like this:

https://img509.imageshack.us/img509/2503/paperzn3.png

Now, I have to find the general expression for the area of the unique shape up thar ^, with the formula in terms of the length L and the width W of the A4 paper.

Ive tried, Ive cried, and i have nothing. Any help would be apreciated

2008-04-28 02:49:40

#2

AussieReaper: ( ͡° ͜ʖ ͡°); +5,761|6191|what

It's a square\rectangular based pyramid. There's maths formula's for those on the net...

searches...

this is stupid. i can't find any examples for this sort of problem on the net. apart from using the obvious maths formulas to work out a pyramid, i can't help. sorry.

Last edited by TheAussieReaper (2008-04-28 03:00:37)

2008-04-28 03:01:45

#3

~Smokey~: Steve Irwin Reincarnate; +396|6576|Internetfitlerland

TheAussieReaper wrote:
It's a square\rectangular based pyramid. There's maths formula's for those on the net...

searches...

this is stupid. i can't find any examples for this sort of problem on the net. apart from using the obvious maths formulas to work out a pyramid, i can't help. sorry.

Im thinking its a bit more complicated than that. The area of a pyramid being BH/2 ?

2008-04-28 03:02:23

#4

tazz.: oz.; +1,338|6212|Sydney | ♥

I really dont get what your doing in the first place... Please explain......

Just to clarify, your folding the piece of paper from corner to corner and creating a pyramid?

Last edited by tazz. (2008-04-28 03:02:54)

^{everything i write is a ramble and should not be taken seriously.... _{seriously. ♥}}

2008-04-28 03:08:52

#5

~Smokey~: Steve Irwin Reincarnate; +396|6576|Internetfitlerland

tazz. wrote:
I really dont get what your doing in the first place... Please explain......

Just to clarify, your folding the piece of paper from corner to corner and creating a pyramid?

Ok,I am folding a piece of A4 paper by joining two two diagonally opposite corners.

eg.

https://img241.imageshack.us/img241/9577/paper2nw3.png

2008-04-28 03:24:44

#6

FEOS: Bellicose Yankee Air Pirate; +1,182|6449|'Murka

Wouldn't that form a pyramid with a square base and equilateral triangles on the side?

Is it the surface area or the area under the pyramid?

If it's the entire surface area, it's the same as the surface area of one side of the A4 paper, unfolded (l x w).

If it's the area under the pyramid, it's l x w of two sides of the base of the pyramid.

Or am I being too simplistic?

“Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid.”
― Albert Einstein
Doing the popular thing is not always right. Doing the right thing is not always popular

2008-04-28 03:38:14

#7

~Smokey~: Steve Irwin Reincarnate; +396|6576|Internetfitlerland

FEOS wrote:
Wouldn't that form a pyramid with a square base and equilateral triangles on the side?

Is it the surface area or the area under the pyramid?

If it's the entire surface area, it's the same as the surface area of one side of the A4 paper, unfolded (l x w).

If it's the area under the pyramid, it's l x w of two sides of the base of the pyramid.

Or am I being too simplistic?

The key to the whole thing is

~Smokey~ wrote:
with the formula in terms of the length L and the width W of the A4 paper.

That

2008-04-28 03:52:16

#8

some_random_panda: Flamesuit essential; +454|6428

Sorry smokey, I did that sort of maths about 2 years ago, and you don't do shape geometry in VCE.

2008-04-28 04:23:26

#9

~FuzZz~: .yag era uoy fi siht deaR; +422|6360|Orrstrayleea

Sorry Smokay, I dont Pay attention in maths, my teacher is a fat, wide-eyed bullfrog.

I hope you read this Ms.Irvine, Get a life, I mean what the fuck do you do? Go home, mark homework, see what i write to you on my sheets, then write letters to my parents? FUCK YOU!

2008-04-28 05:34:35

#10

~Smokey~: Steve Irwin Reincarnate; +396|6576|Internetfitlerland

bl AU squad

/waits for EU/US

2008-04-28 07:06:17

#11

Jestar: Shifty's Home Number: 02 9662 8432; +373|6779

AU section is dumb

2008-04-28 11:45:14

#12

tahadar: Sniper!!; +183|6776|Pakistan/England

the area is BH/2 + W * (L^2 - W^2) / (4L)

dont you dare try and ask how i got it...i need to study for exams and your question just wasted 15 mins for me!

2008-04-29 01:06:49

#13

~Smokey~: Steve Irwin Reincarnate; +396|6576|Internetfitlerland

tahadar wrote:
the area is BH/2 + W * (L^2 - W^2) / (4L)

dont you dare try and ask how i got it...i need to study for exams and your question just wasted 15 mins for me!

Ty mate, sat down today and stared at it for a while and eventually got that

+1 to you sir

2008-04-29 01:22:26

#14

d4rkph03n1x: Member; +131|6787

Jestar12345 wrote:
AU section is dumb

What do you expect? We're descended from convicts.

2008-04-29 01:44:01

#15

beerface702: Member; +65|6731|las vegas

I think you need to find the total surface area first, then use algebralol..what do i know, i barely algebra in highschool ..squeeked by with a C

2008-04-29 02:16:00

#16

Scorpion0x17: can detect anyone's visible post count...; +691|6804|Cambridge (UK)

~Smokey~ wrote:
tahadar wrote:
the area is BH/2 + W * (L^2 - W^2) / (4L)

dont you dare try and ask how i got it...i need to study for exams and your question just wasted 15 mins for me!
Ty mate, sat down today and stared at it for a while and eventually got that

+1 to you sir

Are you sure this is right?

When I first read the OP I thought I understood the problem...

Then people started talking about pyramids...

And that equation uses the terms 'B' and 'H'...

2008-04-29 02:49:24

#17

tahadar: Sniper!!; +183|6776|Pakistan/England

its an entirely 2-dimensional problem. pyramids are 3-d. i think the people talking about pyramids got confused by the question. anyways, smokey got the same answer so we must have done it right!

2008-04-29 02:52:27

#18

Scorpion0x17: can detect anyone's visible post count...; +691|6804|Cambridge (UK)

tahadar wrote:
its an entirely 2-dimensional problem. pyramids are 3-d. i think the people talking about pyramids got confused by the question. anyways, smokey got the same answer so we must have done it right!

In that case, where are you getting B and H from?

2008-04-29 03:57:31

#19

~Smokey~: Steve Irwin Reincarnate; +396|6576|Internetfitlerland

For those interested:

(L-X)^2 = X^2 + w^2
L^2 - 2LX + x^2 = w^2 + X^2
L^2 - w^2 = 2LX
L^2 - w^2 / 2L = X

1/2w x L^2 - w^22 / 2L

LW / 2 + w(L^2 - w^2) / 4L
2L^2w + w(L^2 - w^2) / 4L
w(2L^2 + (L^2 - w^2))
w(2L^2 + L^2 - w^2)
w(3L^2 - w^2) / 4L
3wL^2 - w^3 / 4L

Was fun

Edit:

tahadar wrote:
its an entirely 2-dimensional problem. pyramids are 3-d. i think the people talking about pyramids got confused by the question. anyways, smokey got the same answer so we must have done it right!

I didnt get the exact same as you, I think mines simplified a little more

Last edited by ~Smokey~ (2008-04-29 03:59:37)

2008-04-29 04:01:05

#20

Scorpion0x17: can detect anyone's visible post count...; +691|6804|Cambridge (UK)

~Smokey~ wrote:
For those interested:

(L-X)^2 = X^2 + w^2
L^2 - 2LX + x^2 = w^2 + X^2
L^2 - w^2 = 2LX
L^2 - w^2 / 2L = X

1/2w x L^2 - w^22 / 2L

LW / 2 + w(L^2 - w^2) / 4L
2L^2w + w(L^2 - w^2) / 4L
w(2L^2 + (L^2 - w^2))
w(2L^2 + L^2 - w^2)
w(3L^2 - w^2) / 4L
3wL^2 - w^3 / 4L
Was fun

Edit:

tahadar wrote:
its an entirely 2-dimensional problem. pyramids are 3-d. i think the people talking about pyramids got confused by the question. anyways, smokey got the same answer so we must have done it right!
I didnt get the exact same as you, I think mines simplified a little more

cba to check it, but that looks better.

BF2S Forums So I have this problem... (math problem)

TheAussieReaper wrote:

tazz. wrote:

FEOS wrote:

~Smokey~ wrote:

tahadar wrote:

Jestar12345 wrote:

~Smokey~ wrote:

tahadar wrote:

tahadar wrote:

tahadar wrote:

~Smokey~ wrote:

tahadar wrote:

Board footer