Question

What scale factor was used to create the dilation below centered at point C?

Answer 1

-2

Explanation:

You want to know the dilation scale factor that gives triangle A'B'C from triangle ABC.

Scale factor

We notice that point A' is 4 units down and 2 units right of C, whereas A is 2 units up and 1 unit left of C. The ratio of these distances is the scale factor.

If up and right are positive, then ...

k = (A' -C)/(A -C) = (2, -4)/(-1, 2) = -2

The dilation scale factor is -2.