I’m confused because I don’t know what I would put for “What scale factor takes the original polygon to its smaller copy”.

Look at the sides you’ve labeled CD. On the left figure this is 4 units long. On the right figure it’s only 1 unit long. Going from the bigger to the smaller, you’re not 1/4 the size it started at. That’s a scale factor of 1/4.

Scale factors are:
- greater than 1 if there’s growth
- less than 1 if the result is smaller.