Transformations: Dilations

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Transformations Dilations
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Dilations

• Tell me what you already know!

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Dilations
Dilations video clip
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Dilations Lesson Objectives

• You will be able to
• Describe a dilation
• Find the coordinates of a dilated polygon
• Graph a polygon and its dilation and
• Describe the change in area of a dilated polygon.

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Dilations

• A dilation is a transformation that changes
  the size but the shape of
• an object.

Every dilation has a fixed point that is called
the center of dilation.
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Dilations

• To dilate an polygon
• Graph the polygon.
• Multiply the x and y coordinates of
• each of the polygons vertices by the given
  scale factor.
• Graph the new points.
• Connect the points to form the dilated polygon.

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Dilations
Example 1
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Dilations
Example 1
Multiply each points coordinates by 2 A (1 x
2, 1 x 2) ? A (2, 2) B (1 x 2, 3 x 2) ? B
(2, 6) C (3 x 2, 1 x 2) ? C (6, 2)
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Dilations
Example 1
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Dilations
Example 1
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Dilations

• Your turn

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Dilations

• Your turn

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Dilations

• Sunshine State Standards
• C.1.3.1 The student understands the basic
  properties of, and relationships pertaining to
  two-dimensional regular and irregular geometric
  shapes.
• C.2.3.1 The student understands the geometric
  concepts of symmetry, reflections, congruency,
  similarity, perpendicularity, parallelism, and
  transformations, including flips, slides, turns,
  and enlargements.
• B.1.3.3 The student understands and describes
  how the change of a figure in such dimensions as
  length, width, height or radius affects its other
  measurements such as perimeter, area, surface
  area, and volume.

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Dilations
GeoGebra dynamic worksheets

• Dilation of a square
• Dilation of a circle