Learn how to use the Parallel command to constrain two lines in a sketch so that they extend in the same direction and never intersect in Fusion.
Click Sketch > Constraints > Parallel .
The Parallel constraint icon displays next to the cursor in the canvas.
In the canvas, select the sketch geometry you want to constrain.
The sketch geometry snaps into parallel alignment. A constraint badge displays next to the constrained geometry in the canvas, indicating that the geometry is constrained to remain parallel to each other.