Small challenge

[SlideRule]

Pekis

I used the Line-Circle intersect equations to calculate the coordinates of point D & since the other points can all be derived by rotating the line segment thru points O & B to align with the y axis, the rest is simple trigonometry / geometry using the distance formula, etc.

I've attached a grahpmatica screen capture to illustrate the deviation in the two Arcs thru pts C-D created by the two segments C-A-D (with central angle @ A) & C-O-D (with central angle @ O). The approximate delta is 0.0235.

[attachment=4916]

BEST!
SlideRule

edit: found and corrected numeric typo - omitted a digit!