Civil Geometry Manipulators: A more complex example

In the video below, I show a more complex example of manipulators.  This example is three lines made by the Line Between Points command and two curves made with the Arc Between Elements command.  The arcs were created by clicking a pass-thru point instead of locking a radius.

• In the first manipulation, I drag the rotate arrow on the first line.  This changes the line and in trun changes the first arc.  Why does the arc radius change?  Because the arc was defined with a pass-thru point, this point is held when the line change is made.  This, of course, results in a new radius.
• Then I undo the line change and click the curve radius and type a new value.  This changes the curve from a pass-thru constraint to a locked radius constraint.
• Third, I repeat the line rotation change of the first line.  This time the curve radius remains fixed because it is now defined as a radius rule instead of a pass-thru rule.