Line/A,A
Chord Between Arc Endpoints
Creates a chord line connecting the end point of one arc to the start point of another arc.
What It Does
The Line/A,A operator creates a chord line from the end point of arc A1 to the start point of arc A2. This is used to connect arc segments in a profile construction.
Note: If the end point of A1 and the start point of A2 are the same (arcs are tangent), the chord has zero length. Verify arc endpoints before using this operator.
Syntax
Line/A1, A2
Quick Input
A: [first arc — chord starts at its end point]
A2: [second arc — chord ends at its start point]
Direction Selector
No direction selector is required. The result is uniquely determined by the input geometry.
Worked Examples
Setup:
A0: end point = (40, 0)
A1: start point = (70, 20)
Line/A0, A1
→ L0: from (40,0) to (70,20)
Slope = (20-0)/(70-40) = 20/30 = 2/3
Setup (tangent arcs):
A0: end point = (30, 40)
A1: start point = (30, 40) [same point]
Line/A0, A1
→ L0: degenerate zero-length line (arcs are tangent)
Analytic Rule
Chord from A1 end point to A2 start point.
Coordinates read directly from arc definitions.
Slope = (y2-y1)/(x2-x1)
Result: Exact analytic chord line.
FAQ
What if the arc endpoints coincide?
If the end of A1 equals the start of A2, the chord is a degenerate zero-length line. This indicates the arcs are tangent at that point. Verify arc endpoints before using this operator.
How do I find arc start and end points?
Use the Geometry Information Display or Show Coordinates panel to view arc properties including start_point and end_point coordinates.