Divide and Conquer

Rating: 2.5
June 9th, 2007

divide_and_conquer.gif Yesterday, Zohar Gilboa, with whom I take a PDE course, asked me the following riddle. I must admit it is probably the riddle I like the least on my site thus far. It is very easy though, and as Zohar told me he really liked it himself, I decided to publish it anyways.

Consider the following image:

divide_and_conquer.gif

Your goals are:

  1. Divide shape 1 (bluish) to two equal parts.
  2. Divide shape 2 (greenish) to three equal parts.
  3. Divide shape 3 (yellowish) to four equal parts.
  4. Divide shape 4 (purplish) to five equal parts.

All the division parts mentioned should be continuous shapes.

The second page contains the solution! Please only visit it after giving the riddle some thought…

Pages: 1 2

6 Responses to “Divide and Conquer”

  1. Ronnie Says:

    Funny.. I looked for a real solution for (4) – AKA geometric solution…
    I believe it is not possible actually (using our B2 knowledge :) ) but that should be proven

  2. Dan Says:

    it sounds like you claim 4 is impossible, Ronnie – did you understand you correctly?

  3. Ronnie Says:

    Yes. I am saying it’s impossible to build it without a using a measuring device, such as a compass- only a straight ruler.
    but I could be wrong, this is just my intuition.

  4. Dan Says:

    Oh, i misunderstood you then – i thought you said task 4 is impossible by any means – which as you guess, would be quite surprising… I didn’t take B2, so i can’t really claim to understand that intuition…

  5. Ronnie Says:

    well.. I’m sorry:)
    Anyway, if it interests you, I saw Yaniv published a review of this subject on “Constructions with a Straight-Edge and a Compass)”. I haven’t read it but it would probably provide insight on this problem.

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