9.6: Dilations
A dilation is an enlargement if the scale factor is greater than 1 and a reduction if the scale factor is between 0 and 1.
What is the scale factor?
What is the scale factor?
For us…center of dilation is always the origin
What would the new vertices of this image be after a dilation with scale factor 2?
What would the new vertices of this image be after a dilation with scale factor 1/2?
19. The image of a button is 6 cm across and 5 times actual size…what is the actual size of the button?
Break time
9.7: Similarity Transformations
What is the series of transformations to bring RST to PYZ?
What is the series of transformations to bring ABCD to NMPH?
A similarity transformation is a composition of rigid motions and/or dilations Two figures are similar if and only if there is a similarity transformation from one figure to the other
Is there a consistent scale factor? Why does it work? Are angles congruent? Is there a consistent scale factor?
Are these circles similar Are these circles similar? Assume G has a radius of 15 and H has a radius of 12
Are ALL circles similar?
Is there a similarity transformation from PAQ to TNO Is there a similarity transformation from PAQ to TNO? Not enough information?
What if the shapes aren’t polygons?
Homework: Section 9.6, pages 590-591: 7-9, 16, 17, 19 Honors: Add 36 Section 9.7, pages 598-599: 8, 9, 11- 13, 15 Honors: Add 17, 18
9.7
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