Posers and Puzzles

Posers and Puzzles

  1. Standard memberwolfgang59
    Mr. Wolf
    at home
    Joined
    09 Jun '07
    Moves
    46124
    23 Mar '09 21:48
    Draw nine dots so that they are arranged in a 3x3 square.

    Can you connect all nine dots with 4 STRAIGHT lines without taking pen (or pencil or chalk or other marking-tool) from paper?

    Is it possible?
  2. Joined
    25 Aug '06
    Moves
    0
    23 Mar '09 22:45
    Yes. Hint: you only need "queen moves" (moves in the 8 directions).
  3. Standard membersonhouse
    Fast and Curious
    slatington, pa, usa
    Joined
    28 Dec '04
    Moves
    52874
    24 Mar '09 00:451 edit
    Originally posted by wolfgang59
    Draw nine dots so that they are arranged in a 3x3 square.

    Can you connect all nine dots with 4 STRAIGHT lines without taking pen (or pencil or chalk or other marking-tool) from paper?

    Is it possible?
    Sho nuff. We got that one in the 8th grade. You just have to think outside the box, so to speak.
  4. Standard memberwolfgang59
    Mr. Wolf
    at home
    Joined
    09 Jun '07
    Moves
    46124
    24 Mar '09 16:41
    Originally posted by sonhouse
    Sho nuff. We got that one in the 8th grade. You just have to think outside the box, so to speak.
    Kids get it quicker than adults.
  5. Joined
    15 Feb '07
    Moves
    667
    24 Mar '09 16:45
    I've heard of a way to connect all 9 dots with only 3 lines, believe it or not. This requires thinking even further outside the box though..
  6. Joined
    07 Sep '05
    Moves
    35068
    24 Mar '09 17:38
    Originally posted by geepamoogle
    I've heard of a way to connect all 9 dots with only 3 lines, believe it or not. This requires thinking even further outside the box though..
    Easy enough if the dots are of finite size, and you've got a very big piece of paper.
  7. Joined
    11 Nov '05
    Moves
    43938
    24 Mar '09 18:12
    Originally posted by wolfgang59
    Draw nine dots so that they are arranged in a 3x3 square.

    Can you connect all nine dots with 4 STRAIGHT lines without taking pen (or pencil or chalk or other marking-tool) from paper?

    Is it possible?
    It's not only possible, I can do it in one line, and one stratight line only. Not that difficult. You really have to think outside the box.
  8. ALG
    Joined
    16 Dec '07
    Moves
    6190
    24 Mar '09 20:06
    Originally posted by FabianFnas
    It's not only possible, I can do it in one line, and one stratight line only. Not that difficult. You really have to think outside the box.
    one straight line? That's impossible!
  9. Standard memberforkedknight
    Defend the Universe
    127.0.0.1
    Joined
    18 Dec '03
    Moves
    16172
    24 Mar '09 21:38
    Originally posted by Thomaster
    one straight line? That's impossible!
    My dots are very small and I'm using a sharpy.
  10. Shanghai
    Joined
    16 Feb '06
    Moves
    115340
    25 Mar '09 00:01
    what if the 3x3 square was not made from the nine dots but they were arranged in some other 3x3 square? in fact arrange them on top of each other and cover them with another dot hence 0 lines
  11. Standard memberforkedknight
    Defend the Universe
    127.0.0.1
    Joined
    18 Dec '03
    Moves
    16172
    25 Mar '09 00:50
    Originally posted by deriver69
    what if the 3x3 square was not made from the nine dots but they were arranged in some other 3x3 square? in fact arrange them on top of each other and cover them with another dot hence 0 lines
    Because then it wouldn't be a square, nor 3x3...?
  12. Joined
    11 Nov '05
    Moves
    43938
    25 Mar '09 06:01
    Originally posted by Thomaster
    one straight line? That's impossible!
    Not at all, I can do it with no difficulty.
    Everytime I present this solution people say "You're cheating!" but I'm not. What they really mean is "You don't do it as it is meant to do!" or "We didn't think of that!".
    So there is definitely a solution for 9 dots and one straight line.
  13. Standard memberwolfgang59
    Mr. Wolf
    at home
    Joined
    09 Jun '07
    Moves
    46124
    25 Mar '09 12:41
    maybe I should have said 9 points rather than dots? and defined point, and line and straight.

    In fact I never really defined "9" did I?
  14. Joined
    11 Nov '05
    Moves
    43938
    25 Mar '09 13:001 edit
    Originally posted by wolfgang59
    maybe I should have said 9 points rather than dots? and defined point, and line and straight.

    In fact I never really defined "9" did I?
    Well, you can always narrow the definition to the extent that only one solution is possible. But the problem stated as it was from the beginning, in lay terms.

    Put the nine points slighle tilted, roll the paper to a cylindre, and then draw the line around the cylender, hitting three points every turn.

    That's *one* solution, but I assumed that the paper should be finite in size and flat. So my solution is 9 points on a flat paper. You can use a ruler to make the line perfectly straight.

    Why use four lines when one is enough?
  15. ALG
    Joined
    16 Dec '07
    Moves
    6190
    25 Mar '09 14:12
    Originally posted by FabianFnas
    Well, you can always narrow the definition to the extent that only one solution is possible. But the problem stated as it was from the beginning, in lay terms.

    Put the nine points slighle tilted, roll the paper to a cylindre, and then draw the line around the cylender, hitting three points every turn.

    That's *one* solution, but I assumed that the pa ...[text shortened]... can use a ruler to make the line perfectly straight.

    Why use four lines when one is enough?
    Your cilinder trick doesn't work, since the line should remain straight. (what is impoosible on a rolled paper)

    I think I understand how you do it with one line. You take two papers.
    First you hit three dots with a straight line and you 'park' the line in the second paper. You can simply move the dots :-)
Back to Top