Rotations and Dilations.notebook
October 22, 2012
Transformations: Rotations and Dilations
Rotation
When a shape is rotated around a point. We will rotate around the origin (0, 0).
Rules:
Original Image
90 clockwise rotation
(x, y) (y, ­x)
90 counter­clockwise rotation (x, y) (­y, x)
180 rotation (x, y) (­x, ­y)
270 clockwise rotation
270 counter­clockwise rotation (x, y) (­y, x)
(x, y) (y, ­x)
Rotate 90° clockwise around the origin.
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Rotations and Dilations.notebook
October 22, 2012
Rotate 180° clockwise around the origin
Rotate 270° counter­clockwise around the origin.
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Rotations and Dilations.notebook
Dilation
October 22, 2012
When a shape gets larger or smaller by a constant factor.
Center will be the origin.
Multiply your coordinates by the scale factor.
Dilate the square by ½ and by 3.
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Rotations and Dilations.notebook
October 22, 2012
Rigid Transformation, Rigid Movement or Isometry
When the original and new transformed figure are congruent.
Which transformations are rigid or isometric?
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