# do you know geometry?

Discussion in 'Electronic Design' started by RichD, Aug 23, 2013.

1. ### RichDGuest

Draw an outline of a shape, such that when cut
out with scissors, it will fold into a cube.
You're permiited to draw interior folding lines.

Everyone here will regard this as trivial. But
I've tested it on 6 people, and only 2 got it
associates.

2. ### Don YGuest

You can do it with a *square* piece of paper.

3. ### George HeroldGuest

Weird.. do they only do five 'pieces' a base and four sides?

4. ### m IIGuest

My problems are the interior folding lines. When I try to draw them, I
don't have an interior anymore. There is something Zenish going on here.

mike

5. ### m IIGuest

So...you're implying that it's my *unfolding* of the box that causes the
interior to disappear...This three dimensional space of yours is
certainly taking getting used to.

mike

6. ### Robert BaerGuest

Maybe because there are so many ways it can be done?
I thought of 2 ways in less than 2 minutes and quit because it is so
simple.

Check.

8. ### Don YGuest

Hi David,

Exactly. There was no mention as to how *complex* the folding
process was expected to be.

(Nor any mention as to whether or not the folded paper would *hold*
the shape of its own accord)
Yes. I know of at least two different ways of folding a
perfectly *square* piece of paper into a cube (without the
benefit of scissors). I could probably come up with more
if pressed...

And, by extension, any rectangular piece of paper (I think all
I need is a right angle, somewhere).

You just have to NOT think in "pedestrian" turns. Think
outside the box -- er, *cube*! :>

9. ### Martin RiddleGuest

I got a 11 x 17" piece of paper here.....

Am I allowed to use a ruler?

Cheers

10. ### Jasen BettsGuest

there's several shapes that work

[]
[][][][]
[]

[]
[][][][]
[]

[]
[][][][]
[]

[]
[][][][]
[]

[]
[][][][]
[]

[][]
[][]
[][]

[][][]
[][][]

[]
[][][]
[][]

possibly posibly others too...

11. ### Jasen BettsGuest

I stopped looking after finding 8

12. ### Jasen BettsGuest

Even if you are it won't be a perfect cube, so presumably any
recognisable approximation is acceptable.

If you start with an acceptably rectangular piece of paper, by folding
it you can create a regular square grid. (fold a 45 degree angle to
translate east-west measure to north-south)

13. ### Jasen BettsGuest

When covering the surface of a cube one must think outside the box

14. ### Robert BaerGuest

OR:
_ _
| |
_ _|_ _| <-- top
| | |
_ _|_ _|_ _| <-- front,right
| | |
|_ _|_ _| <-- left,bottom
| |
|_ _| <-- back

This gets rid of the boring 4-in-a-row design.

15. ### Robert BaerGuest

Here is a collection of some of those given:

1A 1B 2A 2B
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
| | | | | | | | | | | |
|_ _|_ _|_ _| _ _|_ _|_ _ |_ _|_ _|_ _ |_ _|_ _|
| | | | | | | | | | |
|_ _| |_ _|_ _|_ _| |_ _|_ _| |_ _|_ _
| | | | | | | | |
|_ _| |_ _| |_ _| |_ _|_ _|
| | | | | | | |
|_ _| |_ _| |_ _| |_ _|

2C 3 var A var B
_ _ _ _ _ _ _ _ _ _
| | | | | | | | |
|_ _|_ _| |_ _|_ _ _ _|_ _| |_ _|_ _
| | | | | | | | | | |
|_ _| _ _|_ _|_ _| _ _|_ _|_ _| |_ _|_ _|_ _
| | | | | | | | | | |
|_ _|_ _ |_ _|_ _| |_ _|_ _| |_ _|_ _|
| | | | | | | | |
|_ _|_ _| |_ _| |_ _| |_ _|

var C
_ _
| |
|_ _|
| |
_ _|_ _|
| | |
|_ _|_ _|
| |
|_ _|
| |
|_ _|

16. ### Jasen BettsGuest

I just thought up some more...
_ _ _ _ _ _
| | | | |
|_ _|_ _| |_ _|
| | | |
|_ _|_ _ _ _|_ _|_ _
| | | | | | |
|_ _|_ _| |_ _|_ _|_ _|
| | | |
|_ _| |_ _|

Having one tile different to "1B" and "2B" or "Var A" or "Var C"
I can's see how to classify them

That makes 11, I can't as yet complete the dozen, if that's possible.

Maybe you should learn to read. I did not see where it was him making
that remark.

Maybe you should learn to read. I did not see where it was him making
that remark.

19. ### m IIGuest

Mister Baer, please report to the Accounting office NOW!

mike

20. ### Robert BaerGuest

Yep!
How about a strip of paper of uniform width (== box size)?
Use 45 degree fold after front, top, back, bottom are made - to allow
sides. Nothing was said about doing a surface twice..