Given a center point of, say, a bolt hole circle, how would you get the angle from the center point to the tangent of any given circle in the bolt hole pattern? The circles are all at different distances from the center point and all circles are of different diameters.
There are many ways to skin the cat... so to speak.
one method that comes to mind, using simple geometry - treat the tools of the software like a compass and straight edge.
Set origin on the center point
Construct point on this center point
Construct diameter(at origin) whose radius is equal to the radial location of one of the holes.
Construct point intersection where constructed circle and diameter meet(choose the side you want the line on.
Construct line thru the center point and this intersection point.
Done.
