Geometry
is
the
branch
of
mathematics
dealing
with
spatial
relationships.
From
experience,
or
possibly
intuitively,
people
characterize
space
by
certain
fundamental
qualities,
which
are
termed
axioms
in
geometry.
Such
axioms
are
insusceptible
of
proof,
but
can
be
used
in
conjunction
with
mathematical
definitions
for
points,
straight
lines,
curves,
surfaces,
and
solids
to
draw
logical
conclusions.
Because
of
its
immediate
practical
applications,
geometry
was
one
of
the
first
branches
of
mathematics
to
be
developed.
Likewise,
it
was
the
first
field
to
be
put
on
an
axiomatic
basis,
by
Euclid.
The
Greeks
were
interested
in
many
questions
about
ruler-and-compass
constructions.
The
next
most
significant
development
had
to
wait
until
a
millennium
later,
and
that
was
analytic
geometry,
in
which
coordinate
systems
are
introduced
and
points
are
represented
as
ordered
pairs
or
triples
of
numbers.
This
sort
of
representation
has
since
then
allowed
us
to
construct
new
geometries
other
than
the
standard
Euclidean
version.
The
central
notion
in
geometry
is
that
of
congruence.
In
Euclidean
geometry,
two
figures
are
said
to
be
congruent
if
they
are
related
by
a
series
of
reflections,
rotations,
and
translationss.