Pearson Geometry Common Core, 2011
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Pearson Geometry Common Core, 2011 View details
6. Dilations
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Exercise 1 Page 590

Recall that a scale factor is the ratio of a length on the image to a corresponding length on the preimage.

Dilation: Enlargement
Scale Factor: 1.5

Practice makes perfect

Before we begin, recall that a dilation is a transformation that enlarges or reduces the original figure proportionally. There are two types of dilation.

  1. Enlargement: The image is larger than the original figure, and is produced by a scale factor greater than 1.
  2. Reduction: The image is smaller than the original figure, and is produced by a scale factor less than 1.
We will determine the given dilation first. Then we can find the scale factor.

Dilation

Let's analyze the given dilation.

We can tell that the blue image is bigger than the black preimage. Therefore, the dilation is an enlargement.

Scale Factor

The scale factor is the ratio of a length on the image to a corresponding length on the preimage. We are given the lengths of the corresponding sides of our figures.

Finally, we can find the scale factor. 12/8=1.5 The scale factor of our dilation is 1.5.