The value of r is given from the combined scale factor transforms ABCD to
A''B'C''D'' and the scale factor that transforms ABCD to A'B'C'D'.
Scale factor of dilation of square ABCD to give the image A'B'C'D' = r
Scale factor of dilation to give square A''B''C''D'' from A'B'C'D' = 1/4
Side lengths of square A''B''C''D'' = 1/8 × Side lengths of square ABCD
The value of the scale factor r.
From the question, we have;
Scale factor of dilation of square ABCD to give the image A''B''C''D'' = 1/8
Combining the sale factors gives;
[tex]\displaystyle r = 4 \times \frac{1}{8} = \frac{1}{2}[/tex]
Learn more about the scale factor of a dilation here:
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