Dividing-the-Plane Puzzles 103Il ~ Q- • Q •
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- SIX STRAIGHT FENCES
A man had a small plantation of thirty-six trees, planted in the form of a
square. Some of these died and had to be cut down in the positions indicated
by the dots in our illustration. How is it possible to put up six straight fences
across the field, so that everyone of the remaining twenty trees shall be in a
separate enclosure? As a matter of fact, twenty-two trees might be so enclosed
by six straight fences if their positions were a little more accommodating, but
we have to deal with the trees as they stand in regular formation, which
makes all the difference.
Just take your pencil and see if you can make six straight lines across the
field so as to leave every tree separately enclosed.
- DISSECTING THE MOON
In how large a number of pieces
can this crescent moon be cut with
five straight cuts of the knife? The
pieces may not be piled or shifted
after a cut.