The document discusses line symmetry in nature, architecture, and shapes. It provides examples of line symmetry in shells, starfish, crabs, masks, the human face, reflections in water, and structures like the Taj Mahal. Specific animals and objects mentioned include butterflies, shells found at the beach, crab shells, starfish, masks from different cultures, and the famous artwork by Leonardo Da Vinci depicting human proportions. Geometric shapes like equilateral triangles, squares, pentagons, hexagons, and octagons are analyzed and their number of internal angles and lines of symmetry identified.

1. Symmetry:Symmetry:
A Visual PresentationA Visual Presentation

2. Line SymmetryLine Symmetry
 Shape has line symmetry when one halfShape has line symmetry when one half
of it is the mirror image of the other half.of it is the mirror image of the other half.
 Symmetry exists all around us and manySymmetry exists all around us and many
people see it as being a thing ofpeople see it as being a thing of
beauty.beauty.

3. Is a butterfly symmetrical?Is a butterfly symmetrical?

4. Line Symmetry exists inLine Symmetry exists in
nature but you may notnature but you may not
have noticed.have noticed.

5. At the beach there areAt the beach there are
a variety of shells with linea variety of shells with line
symmetry.symmetry.

6. Under the sea there are alsoUnder the sea there are also
many symmetrical objectsmany symmetrical objects
such as these crabssuch as these crabs
and this starfish.and this starfish.

7. Animals that have LineAnimals that have Line
SymmetrySymmetry
Here are a few more great examples ofHere are a few more great examples of
mirror image in the animal kingdom.mirror image in the animal kingdom.

8. THESE MASKS HAVETHESE MASKS HAVE
SYMMETRYSYMMETRY
These masks have a line ofThese masks have a line of
symmetry from the forehead to thesymmetry from the forehead to the
chin.chin.
The human face also has a line ofThe human face also has a line of
symmetry in the same place.symmetry in the same place.

9. Human SymmetryHuman Symmetry
The 'Proportions of Man'The 'Proportions of Man'
is a famous work of artis a famous work of art
by Leonardo da Vinciby Leonardo da Vinci
that shows the symmetrythat shows the symmetry
of the human form.of the human form.

10. REFLECTION IN WATERREFLECTION IN WATER
If an object isIf an object is
reflected in water itreflected in water it
is considered tois considered to
have line symmetryhave line symmetry
along the waterline.along the waterline.

11. The Taj MahalThe Taj Mahal
Symmetry exists in architecture all aroundSymmetry exists in architecture all around
the world. The best known example ofthe world. The best known example of
this is the Taj Mahal.this is the Taj Mahal.

12. This photograph shows 2 lines of symmetry.This photograph shows 2 lines of symmetry.
One vertical, the other along the waterline.One vertical, the other along the waterline.
(Notice how the prayer towers, called minarets, are reflected in the(Notice how the prayer towers, called minarets, are reflected in the
water and side to side).water and side to side).

13. 2D Shapes and Symmetry2D Shapes and Symmetry
After investigating the followingAfter investigating the following
shapes by cutting and folding,shapes by cutting and folding,
we found:we found:

14. an equilateral triangle has 3 internalan equilateral triangle has 3 internal
angles and 3 lines of symmetry. angles and 3 lines of symmetry.

15.
a square has 4 internal angles and 4a square has 4 internal angles and 4
lines of symmetry. lines of symmetry.

16. a regular pentagon has 5 internala regular pentagon has 5 internal
angles and 5 lines of symmetry.angles and 5 lines of symmetry.

17. a regular hexagon has 6 internal anglesa regular hexagon has 6 internal angles
and 6 lines of symmetry .and 6 lines of symmetry .

18.
a regular octagon has 8 internal anglesa regular octagon has 8 internal angles
and 8 lines of symmetry.and 8 lines of symmetry.