Brick Curve / Arch form finding.

Hello all...

I'm presently working on using Grasshopper to generate curved brick structures.  Whilst this question is not strictly related to Grasshopper I thought that the end result would be of use / interest to some of you.  I'm attempting to generate "bricks" along an arc, the span of the arc is known (Line AB), as is the desired brick edge length (shown as chords on the dotted circle).  Im am essentially trying to solve for the diameter of the dotted circle and its center point (C).  The variables within the grasshopper script would be span (X), chord Length (Y) and number of segments to the arch (N).  Lacking the radius or central angle means that Im unable to solve this using my limited knowledge of Trig.

I guess the key issue here is that chord length and number is driving the radius of the arc / circle.  Hence why Im not simply using the divide curve tool. 

Any input members might have would be fantastic and I'd be very happy to share the resulting file.

Thank you!