Don't have time to delve into this right now, but consider this as a basis.
If you have a circle with radius = 1.000
and you wish to surround it with semicircles, one option is to get 90 circles with radius 0.0349 and space them every 4 degrees.
I've made a diagram to explain this better:
http://www.zerostatic.com/diagram.jpg
I would like to space out the red circles so their edges touch. I guess I need to know how many degrees away to place a circle based on the radii ?
Also if I were to place these along an Ellipse, can I use the same formula that a circle would use?
Maybe it makes more sense if I reword this...
If I have a circle who's circumference is known - say 10.5 meters.
And I want to plot two points on that circle who's arc distance need to be 1 meter. How would I calculate this in order to plot the two points on the circumference of the circle?