What does the word symmetry mean?
9.6 - Symmetry
A figure has line symmetry if:
if it can be mapped onto itself by a reflection in a line.
Line of symmetry
9.6 - Symmetry
A figure has line symmetry if it can be mapped onto itself by a
reflection in a line.
A figure can have more than one line of symmetry. For example:
9.6 - Symmetry
How many lines of symmetry do you see?
Verify it with your patty paper
9.6 - Symmetry
How many lines of symmetry do you see?
9.6 - Symmetry
A figure has rotational symmetry if: it can be mapped onto itself
by a rotation of 180° or less about the center of the figure.
Note:
Rotations can
be clockwise
or counterclockwise
Degree of Rotational Symmetry: 120°
9.6 - Symmetry
What is the smallest degree of rotational symmetry?
45°
90°
180°
135°
Are there other degrees of rotation (less than or equal to
180°) that would also make the figure land back on itself?
9.6 - Symmetry
Find the degree(s) of rotational symmetry. Verify it with your patty
paper:
180°
120°
Color matters!
A figure with 180° rotation symmetry: POINT SYMMETRY
9.6 - Symmetry