The
most
common
unit
was
the
foot.
To
measure
the
distance
of
a
path,
someone
walked
heel-
to-
toe
along
it
and
counted
each
time
they
set
down
a
foot.
If
they
set
down
their
feet
20
times,
the
path
was
20
feet
long.
However,
there
was
a
problem
with
using
bodies
as
units
of
measure.
People
are
not
all
the
same
size,
so
the
units
were
not
always
the
same.
People
with
smaller
feet
would
measure
distances
differently
than
people
with
larger
feet.