Unit Theme Symmetry The geometry that studies the

Unit Theme : Symmetry � The geometry that studies the symmetry and all forms of their transformation of it is called Transformation Geometry. edtech 2. boisestate. edu

Practice the chant by Loreen Leedy � � Teacher: 1 -2 -3 Students Repeat: 1 -2 -3 Teacher: A-B-C Students Repeat: A-B-C

Seeing Symmetry � Here and there And everywhere We can see Symmetry! Our two eyes See butterflies A perfect square A teddy bear The number 3 The letter Z Most any car A shiny star Up and down And all around We can see Symmetry! Here and there And everywhere We can see Symmetry! Our two eyes See butterflies A perfect square A teddy bear The number 3 The letter Z Most any car A shiny star Up and down And all around We can see Symmetry

Seeing Symmetry Video � � Once when you where to look symmetry is all around you. Book Talk By Loreen Leedy

What is Symmetry? Word wall � � � � Symmetry: Having equal parts in two or more direction Reflective Symmetry: The identical reflection of two sides. (Flip) Rotation Symmetry: The rotation around a point. Translation Symmetry: The slides but not turns.

Glide Symmetry: � How many movement do you need?

Sticky Note Activity

Shape Activity Names of Shapes Cloud Butterfly Heart Happy Face Triangle Square Pentagon Hexagon Octagon Decagon Circle Parallelogram Rectangle Lines of Symmetry Lines of (Asymmetrical) Symmetry Lines of Symmetry 0 2 3 More than 3 Infinity 1

Lakeside Reflection � � A still lake reflects sky and trees in Canada. Photograph by Raymond Gehman

REFLECTION SYMMETRY Washington’s North Cascade National Park

What is Reflection Symmetry? � If an object does not emit its own light, it can reflect the light in order to be seen.

Some vocab. for meaning � � Absorb � Reflect � Transmitted The person sees reflected light.

Reflective Mirrors � What � How are they? do we use them?

Butterfly Activity: Just Watch the Butterfly Fly

Reflective Writing � � A Famous Italian inventor and artist named Leonardo da Vinci used to keep a dairy. However, he wanted his thoughts secret so he wrote in mirror writing. Do you know why that is? http: //legacy. mos. org/sln/Leonardo/write. html

Reflective Writing

Objects or Shapes’ Name Circle What does it look like before exploration? Pre image Can you write Yes your name in mirror writing? No Equilateral triangle Yes No Yes No Explain the reason why? What does it look like after Exploration? Image Did you have a Notes misconception ?

Law of Reflection � The normal is the imaginary line that is perpendicular 90 degree to the surface. � LAW of REFLECTION The of incidence = of reflection. �

What is the law of reflection? � � To view an image of an object mirror, you must sight along a line at the image location. As you sight at the image, light travels to your eye along the path shown in the diagram below. The diagram shows that the light reflects off the mirror in such a manner that the angle of incidence is equal to the angle of reflection.

The image point � � Each person sees the image due to the reflection of light off the mirror in accordance with the law of refletion. When each line of sight is extended backwards, they will intersect at the same point, which the image point of the object.

Specular or Diffuse Reflection

Reflection � � � http: //micro. magnet. fsu. edu/primer/lightandcolor/reflectionintro. html Specular Reflection from a smooth, mirrorlike surface. Defuse Reflection- If the surface is rough, the rays of light are reflected in many directions. The angles of incidence and reflection are still equal but the rays appear to be scattered.

Specular Reflection? � � A bundle of many rays of light travel together with the same intensity and direction? Where have you seen it?

Camera Snapshots

Reflective Sym. -Pattern Blocks

Rotational Symmetry- If the object or the image can be rotated and it still looks the same.

The order of Rotational Symmetry � How many matches there as you go once around is called the order.

The order of Rotational Symmetry � The London Eye with an order of symmetry of 32.

Rotational Symmetry � � Following are facts about rotational symmetry: All figures have at least one order of rotational symmetry. (Rotating a figure 360º will always match the original figure).

Homework � � � Search for four symmetry pictures from recycling magazines or newspapers. Clip and paste them in your math journal. Write a reflection if the object is symmetrical. If so, where is the line of symmetry? Construct it! What kind of symmetry is?

Words Vocabulary Flashcards Definition Symmetry The identical reflection of two sides. Transformation or Image (Reflection, Translation, Rotation, and dilation) A transformation changes a figure into another figure. Reflection A transformation in which a figure is reflected in a line called the line of reflection. (mirror image) Rotation A transformation in which a figure is rotated about a point called the center of rotation. The angle of rotation The number of degrees a figure rotates. Translation A transformation in which a figure slides but does not turn. Every point of the figure moves the same distance and in the same direction. The point at which the two sides of an angle meet. A point at which two sides of a polygon meet. The plural of vertex is vertices. Figures that have the same size and the same shape Vertex of an angle Vertex of a polygon Congruent

Symmetry Related Concepts � � � Half vs. Whole Equal vs. Not Equal Vertical vs. Horizontal Repeat- Match (folding shapes) Reflection-Flip- Mirror Image Rotate-Turn

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REFERENCES http: //camillasenior. homestead. com/optics 3. html http: //study. com/academy/lesson/what-is-thelaw-of-reflection-of-light-definition-lessonquiz. html