How can you constrain two lines to be parallel in Fusion 360?

To constrain two lines to be parallel in Fusion 360, the use of the "Parallel" geometric constraint is the most effective and straightforward approach. When this constraint is applied, it ensures that the two selected lines will always maintain a constant angle of 0 degrees between them, meaning they will run alongside each other regardless of any modifications made to their lengths or positions. This is an important aspect of parametric design, where relationships between objects are maintained throughout the design process.

Using the "Equal" constraint does not address the parallelism; it only ensures that the two lines are the same length, which is not the objective here. The "Collinear" constraint applies to lines that lay along the same straight line, rather than maintaining a parallel relationship, which can misrepresent the intended design if the lines are not truly aligned. Manually redefining the angles of the lines can be tedious and lacks the flexibility that geometrical constraints provide, leading to potential inaccuracies and difficulty in making adjustments later on.

Overall, applying the "Parallel" geometric constraint is the preferred method in Fusion 360 for ensuring that two lines remain parallel throughout the design process.