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Trick brain teasers appear difficult at first, but they have a trick that makes them really easy.


Puzzle ID:#21615
Fun:*** (2.11)
Difficulty:** (1.75)
Submitted By:badbunnee*****
Corrected By:iam_not_here




Can you fold a 8.5 in x 11 in (US Standard) piece of notebook or typing paper in half and draw a single 13 inch straight line on ONE of the four faces of the folded paper?


Think of different ways you can fold the piece of paper so it is ALWAYS folded in half.
An unfolded sheet has two sides (faces); front and back. A sheet folded in half has four faces (sides); two each on what was the *front* and two each on what was the *back*.


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Mar 18, 2005

Again, not trick, just SIMPLE math, with the emphasis on Simple, as in simple-minded. Put these in the math category where they belong!
Mar 18, 2005

Hi, unklemyke. Thanks for the visit and the comment. I'm glad you solved it so quickly.

And I'm sure you'll have lots of fun doing it with some of your friends who are not quite so math-savvy !!
Mar 18, 2005

Easy, but fun. Thanks badbunnee
Mar 18, 2005

Thanks, aardvark, I appreciate the visit and comment.

This one works MUCH better *live* and *in person* than textually (as here).

Get with a friend or friends who don't know the *trick* (I've discovered that their *math* skills are largely irrelevant) and go through the instructions verbally step-by-step.

Just say ... *Take this piece of paper and fold it in half*. Almost everyone will fold it vertically or horizontally in the typical, learned manner.

This involves a psychologial phenom known as *set*. Once a person gets *set* in a thought or routine it's hard to break out of it.

Then tell them to draw the 13 in. line on ONE of the four sides.

Don't give them any help, just keep repeating the instructions but don't give any additional help.

Eventually, maybe, one or more of them will figure it out. They must do so, however, by withdrawing from their *set* thinking and rethink the problem. Often very difficult to do when the problem is given verbally in a live situation.

This illustrates, of course, a creative, or *lateral*, or *cluster* thinking capability of some people.
Mar 18, 2005

Kinda like making paper airplanes!
Mar 18, 2005

Ya, frogg !!!

Glad you dropped in and gave it a shot !!!
Mar 18, 2005

Very very fun and interesting
Mar 18, 2005

i tried but it didnt work how do u fold it corner 2 corner
Mar 18, 2005

Hi, runscape.

OK ... Imagine you are looking at the paper page. The upper left corner is UL, the upper right corner is UR, the lower left corner is LL, and the lower right corner is LR. Mark them so with a pencil if you wish.

Now, take the LR corner and move it up toward the UL corner. Don't fold it yet. The paper will be sort of rolled over and up and toward the left and you should have something that looks like a triangle (two cut edges of the paper and a third edge that is not yet folded). Now ... keeping the paper that way, crease (fold) the paper along the line between the two other corners; LL and UR in an exact line from the LL corner point to the UR corner point. That should give you a folded sheet that has four *sides* or *faces*. Each of the sides will be a three-edged shape (a triangle). Draw a line VERY close to the longest edge on ONE of the four faces of your folded paper and it should be a little longer than 13 inches.
Mar 18, 2005

Hey, runscape. Send me back a comment here if you got it ... or PM me if you wish.
Mar 19, 2005

was thinking it was exact oh well im just complicating myself
Mar 19, 2005

Hello, again, KB123. Thanks for the *gay stupid crap* comment !!!

I happen to be a devoted fan of happy, dumb, BS puzzles. More interesting, more fun, and more challenging. Glad you took the time to stop by and take a look.
Mar 19, 2005

Hi, r3lish. Thanks for the visit and comment.

I hope you discovered it needn't be complicated. I've used this puzzle with lots of workshop groups and found they solve it three different ways. It can be solved as a math problem (as unklemyke did above). It can be solved as a logic problem by going through all the possible alternatives of folding a piece of paper in half. It can also be solved as a *creativity* problem by simply looking at the page and *seeing* the longest straight dimension (corner to opposite diagonal corner) and folding it that way. Actually those individuals who jump (sometimes called the *intuitive leap*) to the creative approach will get the solution faster and easier.

But that, of course, involves a non-traditional way of folding a sheet of paper.
Mar 20, 2005

My head hurts!!!
Thats hard.
Mar 23, 2005

To freezequeen: Thanks for taking a shot at it.

Yes, it CAN be difficult, but read my comment immediately preceding your comment about several ways to solve it. AND .... thanks for your comments on a couple other of my rebuses. I read those, too.
Apr 01, 2005

to baddbunny your coments on your teaser make my head hert

and have u ever tryed to fold a pice of paper diagnaly eaven if u hold the side the paper twists to mak an eser fold but in reality its not dooing what u want it to do and i hope this is making your head hert too becuse its making my feble litle brain try and morph into it when i want to go threw it

the mening to life is cheese
Apr 23, 2005

To krabbie ...

Whenever I do this puzzle with workshops I find that people work it lots of different ways. Folding the paper diagonally corner-to-corner seems to be a problem with about 10% of the group.

Maybe they are "looking" at the problem differently than the others in the group.

Next time I do it I'll try to find out why they have difficulty. And let you know.

Thanks for your visit and your comments. You might want to try this out with some of your friends ... and see how they do it.

Apr 24, 2005

its also posible to draw a line compleatly accross and get a(close to) 14.5 in. line
May 02, 2005

how is 14.5 inches possible. using pythagoreus theorum, only 13.9 inches is possible from diagonal to diagonal. which the line being drawn first may make folding easier.
May 02, 2005

btw, i liked. it was ultimately easy but not immediately easy. also like to have to think for a little bit first. otherwise it's boring.
May 06, 2005

i used the parigarium therum but i mostly did it in myt head so maybe i got 1 of the numbers mixed up
May 06, 2005

Sorry, but i am not the best at math AT ALL... This is totally confusing but its just my opinion other people seem to like it or w/e good job i guess...
May 07, 2005

this is extremely easy
Jun 11, 2005

my answer was just YES
Jul 17, 2005

i just don't get it
Aug 30, 2005

But math-wise, this is not folding a piece of paper in half, correct?
Aug 30, 2005

These are not equal triangles, obviously.
Aug 30, 2005

Ok, I get it... You are not matching the edges. Your instructions for folding are a little confusing. However, you do get the equal triangles that don't "match" on top of each other. 64 + 132.25 = 196.25 so the longest edge of the right triangle is 14 inches and you can draw a 13 inch line. I like it. I rated it well. i just don't care for your instructions via message board. It works better IRL.
Jul 14, 2006

you cant fold it corner to corner and have i in wo halves if it is an 8.5x11 piece of paper
Aug 15, 2007

I suppose this all depends on whether or not you consider folding it that way to truly be considered as folding it in half.
Dec 19, 2008

Look. If you fold it corner to corner, each half has the same area, so why shouldn't it be folding in half? And, person up there, how could a teaser be gay?!
Jul 04, 2009

It said "can you" not "HOW can you" so the correct answer for this teaser would be "Yes"
Aug 22, 2013

i agree to light's comment
shoudn't the answer be "yes"?

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