304 Answers
- SIX STRAIGHT FENCES
The six straight fences are so drawn
that every one of the twenty trees is in
a separate enclosure. We stated that
twenty-two trees might be so enclosed
in the square by six straight fences if
their positions were more accommo-
dating. We will here state that in such
a case every line must cross every
other line without any two crossings
coinciding. As there are in our puzzle
only twenty trees, this is not neces-
sary, and it will be seen that four of
the fences cross only four others
instead of five.
12- DISSECTING THE MOON
The illustration shows that the five
cuts can be so cunningly made as to
produce as many as twenty-one pieces.
Calling the number of cuts n, then
in the case of a circle the maximumnumber of pieces will be n^2 i n + I,
but in the case of the crescent it will
b e n^2 + 2 3n +. 1- DRAWING A STRAIGHT LINE
Take pieces of thick cardboard (they need not have straight edges!) and join
them with shoemakers' eyelets, as in the illustration. The two long pieces are
of equal length from center of eyelet to eyelet, and the four pieces at the bot-