I wonder how many
of my readers, amongst those who
have not given any close attention to the elements of geometry, could
draw a regular pentagon, or five-sided figure, if they suddenly
required to do so.
A regular hexagon, or six-sided figure, is easy
enough, for everybody knows that all you have to do is to describe a
circle and then, taking the radius as the length of one of the sides,
mark off the six points round the circumference.
But a pentagon is
quite another matter.
So, as my puzzle has to do with the cutting up of
a regular pentagon, it will perhaps be well if I first show my less
experienced readers how this figure is to be correctly drawn.
Describe
a circle and draw the two lines H B and D G, in the diagram, through
the centre at right angles.
Now find the point A, midway between C and
B.
Next place the point of your compasses at A and with the
distance A D describe the arc cutting H B at E.
Then place the point of
your compasses at D and with the distance D E describe the arc cutting
the circumference at F.
Now, D F is one of the sides of your pentagon,
and you have simply to mark off the other sides round the
circle.
Quite
simple when you know how, but otherwise somewhat of a poser.
Having formed your
pentagon, the puzzle is to cut
it into the fewest possible pieces that will fit together and form a
perfect square.
See answer