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Cut Wire (Posted on 2005-05-20) Difficulty: 3 of 5
A piece of wire is to be cut into two pieces (one bent into the shape of a regular p-gon and the other a regular q-gon).

If

1) p = 2*q,
2) 2*perimeter(q-gon) = 3*perimeter(p-gon), and
3) the sum of the two areas is minimized;

then what is the value of q?

See The Solution Submitted by Bractals    
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Solution Agree | Comment 5 of 7 |
I think I agree with Charlie here. From (2) we get that the p-gon perimeter is 60% of the wire, and the q-gon perimeter is the other 40%. Whatever p and q, we can always find a radius such that we get a p-gon or q-gon with the given perimeter. So, all we need is to minimize the sum of their areas. From (1), the q-gon is at least a triangle, and the p-gon is at least an hexagon. If x<y, an x-gon is smaller than a y-gon. So, if we take both minimums (q=3, p=6) we satisfy (3).

  Posted by Old Original Oskar! on 2005-05-21 01:03:58
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