Notes 3­5 Symmetry.notebook
November 14, 2013
Warm Up
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Notes 3­5 Symmetry.notebook
November 14, 2013
3-5 Symmetry
Objective: Identify types of symmetry in objects.
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Notes 3­5 Symmetry.notebook
November 14, 2013
A figure has symmetry if there is an isometry that maps the
figure onto itself.
OHIO
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Notes 3­5 Symmetry.notebook
November 14, 2013
A plane figure has reflectional symmetry or line
symmetry if there is a reflection that maps the
figure onto itself.
If you fold a figure along a line of symmetry,
the halves match exactly.
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Notes 3­5 Symmetry.notebook
November 14, 2013
A figure has rotational symmetry if there is a rotation
of 180° or less that maps the figure onto itself.
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Notes 3­5 Symmetry.notebook
November 14, 2013
A rotation of 180° is known as a half-turn.
If a half-turn maps a plane figure onto itself,
the figure has point symmetry.
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Notes 3­5 Symmetry.notebook
November 14, 2013
What types of symmetry does each figure have?
If it has reflectional, sketch the lines of symmetry.
If it has rotational, state the angle of rotation.
Does it have point symmetry?
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Notes 3­5 Symmetry.notebook
November 14, 2013
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Notes 3­5 Symmetry.notebook
November 14, 2013
Symmetry in Nature Video
http://www.youtube.com/watch?v=fCKILUeV1xk
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Notes 3­5 Symmetry.notebook
November 14, 2013
HW # 41
Practice 3-5
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