Matt Maurer 3rd Grade

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Congruency, Similarity, and Symmetry

• By
• Matt Maurer 3rd Grade

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North Carolina SCOS Objectives

• Math objectives 2.1 and 2.2 from the old
  curriculum
• Technology objectives 1.11, 3.01

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EQ How are congruent figures, similar, figures,
and lines of symmetry related?
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Congruent Figures

• Are figures that have the same shape and size.
• Example

These shapes are congruent!
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Congruent Figures, contd

• Important Fact Figures are still congruent even
  if one of them is rotated or turned.
• Examples

Notice these shapes are turned, but they are
still the same size and congruent!
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Similar Figures

• Are figures that have the same shape, but not the
  same size
• Examples

Notice these figures are the same shape, but
different sizes.
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Important fact Similar figures are still
similar even if one of them is turned or
rotated.

• Examples

These figures are still the same shape even
though they are rotated, just different sizes.
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Line(s) of Symmetry

• A line of symmetry is a line that a figure can
  folded on so that each part matches exactly.
• Example

Is this a line of symmetry?
No!
Is this a line of symmetry?
Yes!
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Symmetrical Figures

• Symmetrical figures are figures that can be
  folded so that two sides match exactly.
• Some examples of symmetrical figures

A
U
Can you trace the lines of symmetry with your
finger?
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Lets Practice!

• Congruent or Not!

Yes No
Yes No
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Lets Practice!

• Similar or Not!

Yes No
Yes No
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Lets Practice!

• Lines of symmetry

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Congruent or Similar

• Name whether the figures below are congruent or
  similar.
• 2.
• 4.
• 5. 6.

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EOG Practice!

• You may see this on the EOG test!
• Which word best describes the butterflies below?

A Similar B Congruent C Plane Figures D
Polygon
If you answered similar, give yourself a pat on
the back!
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EOG Practice!

• You may see this on the EOG test!
• Which one of these
• shapes could have more
• than two lines of symmetry?

A Clown face B Menora C Sun D Heart