I would like to make a dynamic circle with the inner radius ($R_a(t)$) moving to $R_b$ like the image below. I had difficulty using Manipulate and leaving the intersections colored as in the image. Would anyone know how to do it that way?
Thank you very much for your attention!
Disk
s of decreasing radius stacked one on top of the other, or as twoAnnulus
es. $\endgroup$