Odd Tangent behaviour

[etfrench]

The line is being extended instead of the circle moving to be tangent with the line.  The sketch is an imported dxf.

[laughingcreek]

That imported DXF is a mess.  your going to struggle with this sketch till you redraw it (in a seperate sketch) with native fusion geometry.  till things get locked down with constraints and dims,  it's difficult to predict what will move to what.  it looks like its creating the tangent way off to the side of the screen .  remember, tangent doesn't mean coincident.   a line can be tangent and not be touching the circle 

[etfrench]

The contours are polylines.  The originating app doesn't do splines.

The circle should be tangent to the line as it was selected first, not the line tangent to the circle 😀   Even so, the extended line is not tangent to anything.

The normal procedure for these dxfs is to extrude first, convert to mesh, then use mesh tools to create the contour splines. 

[davebYYPCU]

When I fixed that small line, the circle with slight delay, jumps to become tangent / coincident with both outlines?

Might help....

[laughingcreek · Accepted solution]

pick order doesn't matter.  if a line is completely unconstrained, and a circle is completely unconstrained, the line will always move too be tangent to the circle.  in this case the short segment is trying to move to be tangent with the circle.  it's also trying to satisfy it's other constraints.  the short line is moving way off to the side, but it is ending up tangent. the line that appears to be getting extended is the one connected to it.

[etfrench]

99% of the time, the first item chosen in the Tangent operation moves to the second, so I assumed that was the expected behaviour. So, the odd tangent behaviour is explained, but it's still odd 😊