What is the answer?

Question

circle d has radius 3 and circle f has circumference 24 π what is the scale factor of the dilation that transform circle d into circle f (C=π2πr) (12.1 Scale factor)

Answer 1

The scale factor, k, is the ratio of the radius of circle f to the radius of circle d:

k = r_f / r_d

The radius of circle d is given, r_d = 3. You can find the radius of circle f using the circumference info:

C = 2π·r_f

24π = 2π·r_f

Solve for r_f then use the values of r_d and r_f to get the scale factor k.