Geometry, Teacher\'s Edition

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  3. Point symmetry- looks the same right side up and upside down. It looks the same from the left and from
     the right.
  
  
  
  


• Three dimensional


• Planes of symmetry- divide a 3Dfigure into two parts that are reflections of each other. Think of a cylinder or
  cube.

IV.AlternativeAssessment

• There are several ways to assess student understanding in this lesson.


• The first way is with the images to represent each type of symmetry.


• The second is with the partial images and completions.


• Collect student work and check to see that student work is complete and accurate.


• Provide students with feedback or corrections.

Dilations

I.SectionObjectives

• Use the language of dilations.


• Calculate and apply scalar products.


• Use scalar products to represent dilations.

II.MultipleIntelligences

• To differentiate this lesson, begin by teaching the concepts in the lesson to the students.


• Then, students are going to create their own dilations using scalar multiplication.


• Students will need graph paper, rulers and colored pencils.


• Ask the students to show all of their work.


• Here are the steps to the activity.


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  1. Draw a polygon of choice on the coordinate grid.
  
  
  
  


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  2. Use the vertices of the polygon to create a matrix.
  
  
  
  


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  3. Select or use a given scale factor.
  
  
  
  


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  4. Multiply the scale factor with the matrix.
  
  
  
  


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  5. The product is a new matrix- the new matrix is the vertices of the dilated matrix.
  
  
  
  


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  6. Draw in the figure on the coordinate grid.
  
  
  
  


• Allow time for the students to share their work when finished.


• Intelligences- linguistic, logical- mathematical, visual- spatial, interpersonal, intrapersonal

III.SpecialNeeds/Modifications

• Review that a dilation is an image “blown up” or decreased in size.


• Transformations are also dilations.


• Dilations can be written as a matrix.


• Review scale factor.


• Scalar Multiplication- Take the real number and multiply it with each element in a matrix. The product is a
  new matrix.


• To create a dilation on the coordinate grid


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  1. Design a matrix based on the vertices of a polygon drawn on the coordinate grid.
  
  
  
  


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  2. Decide on a scale factor for the dilation.
  
  
  
  

4.12. Transformations