Post Go back to editing

KCC's Quizzes AQQ271 about a Jordan Curve Theorem applied for sheep

New quiz AQQ271 about a Jordan Curve Theorem applied for sheep

  

As one of the most famous theorem in topology (just recently demonstrated in 1980 ,

the Jordan curve (drawn in black) divides the plane into an "inside" region (light blue) and

an "outside" region (pink). Basically, the theorem says all the points (and only those) 

in each of the 2 regions are connected without crossing the border.

It appears obvious but the formal proof was not evident.

Let’s applied it to our sheep spread in- and out-side a bizarre enclosure partially masked by 3 large trees.

Question: Despite of the trees, determine which of the 6 sheep A,B,C,D,E,F are inside and outside the enclosure.

Good luck and try to be among the first ones!

Please share your answer to view other submitted answers
Parents Reply
  • Intriguing..

    Below the more logical approach

    Start with A is outside: '1. out'.
    there is a border above, so the section above must be inside: 2. in'
    again a border: the section above must be outside '3a. out'
    follow that section to 3b.out
    border to 4a. in

    etc

    same result

Children