Page 1 of 2
Challenge : making only 5 points from a single square
Posted: January 4th, 2005, 5:34 pm
by T
I was folding a piece of paper when I thought - is it possible to only have 5 points from a single square?
This becomes very difficult if you include all internal points and class a point as anything from 1-179 degrees.
Ive managed to make 5 points from a rectangle.
Maybe I'm completely missing something.
Has anyone done this?
Posted: January 4th, 2005, 11:32 pm
by mleonard
Maybe I'm missing something - but a waterbomb base has 5 points (four 45-degree points and one 90-degree point).
Posted: January 4th, 2005, 11:55 pm
by saj
Yes, Mark is right. The waterbomb base is the one that popped up in my head too.
saj
Posted: January 5th, 2005, 10:44 am
by T
But then there are internal points created by the reverse folds.. These are inside the model.
It includes every point not just the ones you can see.
Posted: January 5th, 2005, 5:46 pm
by bshuval
If by point you mean "vertex" or "corner", then a square has 4 points.
Folding one corner to the center (say), produces a pentagonal shape that has 5 points.
Posted: January 5th, 2005, 6:04 pm
by T
But the layer folded (the original corner of the square counts as a point.
not just the outside points any point from the entire peice of paper.
Posted: January 5th, 2005, 8:51 pm
by mleonard
Well, your definition of "point" seems a trifle idiosyncratic. Take this example: fold a square in half from side to side. Now how many points does it have?
Considered as a traditional origami base, it has no points at all. By your definition, however, it has six.
But even with this definition it is still fairly easy to create 5 points from a square: fold in half along the diagonal, and then in half again. Voila: 5 points (one of which is hidden inside another one).
Posted: January 5th, 2005, 9:25 pm
by T
Yes technically my definition of a point isnt origami- like but that is the challenge.
However with the diagonal fold in half and then in half again there are 6 flaps as
there is a 90 degree flap at the bottom.
3 on the outside
and 1 hidden
Thanks for your time
Posted: January 6th, 2005, 1:13 am
by JMcK
Fold a square in half diagonally.
Unfold it.
Fold one edge of the square so that it lies along the crease you've just made.
Then, I think, you have five "points".
Posted: January 6th, 2005, 10:57 am
by T
Unfortunately not
just tried it
you make a 5 sided shape which has 5 points and then there is the point that was folded in (the original corner of the square)
I think the challenge might be impossible as to make 1 extra point from a square means that other points will be created.
SO using my definition of a point I believe the challenge is impossible.
Posted: January 6th, 2005, 11:00 am
by T
WAIT I JUST REALISED
I was wrong a few post back folding in half diagonally and the in half diagonnally again produces 5 points not 6.
Therefore this method does it.
So it is possible to make 5 points only fromn a single square by folding in half diagonally and then again diagonally.
Well done!
Posted: January 6th, 2005, 11:22 am
by JMcK
T wrote:Unfortunately not
just tried it
you make a 5 sided shape which has 5 points and then there is the point that was folded in (the original corner of the square)
I think the challenge might be impossible as to make 1 extra point from a square means that other points will be created.
SO using my definition of a point I believe the challenge is impossible.
I musn't have explained this very well - the method I describe produces a 4 sided shape with 4 points and a point (a corner) that is folded in.
I could describe the shape another way by saying that it looks like a kite base that has had one of its flaps unfolded.
And yes, Mark's method works too.
Posted: January 6th, 2005, 1:47 pm
by JMcK
JMcK wrote:
And yes, Mark's method works too.
Oops, just realised that it doesn't. It creates six points - two 45 degree ones, two 90 degree ones and two 112.5 degree ones.
Posted: January 6th, 2005, 9:23 pm
by mleonard
Sorry, I should have realised that my instructions were ambiguous - I meant in half along the diagonal, and then in half again along the other diagonal. This gives a right angled triangle which is one quarter of the area of the original square. The points were correctly described by T:
there is a 90 degree flap at the bottom.
3 on the outside
and 1 hidden
T just made a slight error in saying that 1+3+1=6, before correcting himself.
Posted: January 6th, 2005, 9:51 pm
by JMcK
Sorry, Mark; I see what you mean now.