<s>
In	O
mathematics	O
,	O
reflection	B-Algorithm
symmetry	I-Algorithm
,	O
line	B-Algorithm
symmetry	I-Algorithm
,	O
mirror	B-Algorithm
symmetry	I-Algorithm
,	O
or	O
mirror-image	O
symmetry	O
is	O
symmetry	O
with	O
respect	O
to	O
a	O
reflection	B-Algorithm
.	O
</s>
<s>
That	O
is	O
,	O
a	O
figure	O
which	O
does	O
not	O
change	O
upon	O
undergoing	O
a	O
reflection	B-Algorithm
has	O
reflectional	B-Algorithm
symmetry	I-Algorithm
.	O
</s>
<s>
In	O
2D	B-Algorithm
there	O
is	O
a	O
line/axis	O
of	O
symmetry	O
,	O
in	O
3D	O
a	O
plane	B-Algorithm
of	I-Algorithm
symmetry	I-Algorithm
.	O
</s>
<s>
An	O
object	O
or	O
figure	O
which	O
is	O
indistinguishable	O
from	O
its	O
transformed	O
image	O
is	O
called	O
mirror	B-Algorithm
symmetric	I-Algorithm
.	O
</s>
<s>
In	O
conclusion	O
,	O
a	O
line	B-Algorithm
of	I-Algorithm
symmetry	I-Algorithm
splits	O
the	O
shape	O
in	O
half	O
and	O
those	O
halves	O
should	O
be	O
identical	O
.	O
</s>
<s>
In	O
formal	O
terms	O
,	O
a	O
mathematical	O
object	O
is	O
symmetric	O
with	O
respect	O
to	O
a	O
given	O
operation	O
such	O
as	O
reflection	B-Algorithm
,	O
rotation	O
or	O
translation	O
,	O
if	O
,	O
when	O
applied	O
to	O
the	O
object	O
,	O
this	O
operation	O
preserves	O
some	O
property	O
of	O
the	O
object	O
.	O
</s>
<s>
Thus	O
a	O
square	O
has	O
four	O
axes	B-Algorithm
of	I-Algorithm
symmetry	I-Algorithm
,	O
because	O
there	O
are	O
four	O
different	O
ways	O
to	O
fold	O
it	O
and	O
have	O
the	O
edges	O
all	O
match	O
.	O
</s>
<s>
A	O
circle	O
has	O
infinitely	O
many	O
axes	B-Algorithm
of	I-Algorithm
symmetry	I-Algorithm
.	O
</s>
<s>
Triangles	O
with	O
reflection	B-Algorithm
symmetry	I-Algorithm
are	O
isosceles	O
.	O
</s>
<s>
Quadrilaterals	O
with	O
reflection	B-Algorithm
symmetry	I-Algorithm
are	O
kites	O
,	O
(	O
concave	O
)	O
deltoids	O
,	O
rhombi	O
,	O
and	O
isosceles	O
trapezoids	O
.	O
</s>
<s>
It	O
equals	O
1	O
for	O
shapes	O
with	O
reflection	B-Algorithm
symmetry	I-Algorithm
,	O
and	O
between	O
2/3	O
and	O
1	O
for	O
any	O
convex	O
shape	O
.	O
</s>
<s>
For	O
more	O
general	O
types	O
of	O
reflection	B-Algorithm
there	O
are	O
correspondingly	O
more	O
general	O
types	O
of	O
reflection	B-Algorithm
symmetry	I-Algorithm
.	O
</s>
<s>
with	O
respect	O
to	O
a	O
non-isometric	O
affine	O
involution	O
(	O
an	O
oblique	B-Algorithm
reflection	I-Algorithm
in	O
a	O
line	O
,	O
plane	O
,	O
etc	O
.	O
)	O
</s>
<s>
Animals	O
that	O
are	O
bilaterally	O
symmetric	O
have	O
reflection	B-Algorithm
symmetry	I-Algorithm
in	O
the	O
sagittal	O
plane	O
,	O
which	O
divides	O
the	O
body	O
vertically	O
into	O
left	O
and	O
right	O
halves	O
,	O
with	O
one	O
of	O
each	O
sense	O
organ	O
and	O
limb	O
pair	O
on	O
either	O
side	O
.	O
</s>
<s>
Mirror	B-Algorithm
symmetry	I-Algorithm
is	O
often	O
used	O
in	O
architecture	O
,	O
as	O
in	O
the	O
facade	O
of	O
Santa	O
Maria	O
Novella	O
,	O
Florence	B-Application
.	O
</s>
