A piece of wire is to be cut into two pieces (one bent into
the shape of a regular pgon and the other a regular qgon).
If
1) p = 2*q,
2) 2*perimeter(qgon) = 3*perimeter(pgon), and
3) the sum of the two areas is minimized;
then what is the value of q?
The idea is to minimize the sum of the two areas by choosing q, which must be at least 3, making p at least 6.
The total perimeter is fixed, equal to the total length of the piece of wire. The qgon gets 3/5 of the length of the wire, while the pgon gets 2/5.
As the number of sides is increased, with the same given perimeter, the area enclosed increases, so we want to make the number of sides as small as possible: that makes the value of q 3.

Posted by Charlie
on 20050520 19:15:03 