What you’ll learn
Understand dilations.
Key idea
A dilation uniformly multiplies center distances; its factor is image divided by original, not their difference.
Scale is image/original along the same center ray; additive difference is not the factor.
Worked example
Classify examples and non-examples for the concept 'Understand dilations'.
Dilation about O has OP=4, OP'=16 on the same ray. Classify claim that scale factor is 5.
- Original center distance is 4 and image distance is 16 on the same ray.
- Dilation factor is image/original=16/4=4, not image-original=12.
Answer: False — image/original=16/4=4.
Quick Check
Classify examples and non-examples for the concept 'Understand dilations'.
Dilation about O has OP=9, OP'=9/2 on the same ray. Classify claim that scale factor is 1/2.