Making circles and arcs concentric

Hi,

I drew about 8 concentric circles. I selected them all and used the Concentric constraint.

Later I cut arcs in these circles and added radial and other lines to them.

When I zoom in to a resolution of 0.01 mm, I find that the centres of these arcs is no longer concentric. Is there anyway I can make make these arcs concentric again without having to delete the radial / other lines that connect these arcs?

The image of the centres in the zoomed figure is pasted below:

An image of the arcs and connecting lines is below:

Thanks,
Ajit

Did you try using the Concentric constraint? You have to select only two points for it to be available, I believe. Just keep selecting pairs of points until everything is concentric.