Smart Line Chain
Draw a line chain with constraints. Add tangential circle arcs, perpendicular polylines, and symmetric line hatches.
- Start drawing from the origin. 
- On the  tab, in the Lines group, click tab, in the Lines group, click Smart (smart line chain). Smart (smart line chain).
- Click the start point, drag a straight line first. Continue the line by adding an arc. 
- Select the end point.
- Draw tangential circle arcs, perpendicular polylines, and symmetric line hatches in the sketching mode.As an example, an Arc.  If you select another line's end point as the start point, a tangential spline is drawn. 
- Select Confirm.
