Horizontal lines relation

A line or an axis are horizontal if they are parallel to the x-axis. A horizontal-lines relation is detected automatically and cannot be set and kept, except in the case with axis lines.

To detect a horizontal-lines relation implicitly

This is the common way to make a line segment or an axis line Horizontal (along the x-axis).

1. Place the first control point of a line or axis.
2. Position the preview to be horizontal, that is parallel to the x-axis, until the horizontal-lines relation indicator appears.

note: The horizontal-lines relation can be detected implicitly if the Horizontal line check box in the Tools | Options | Relations tab is selected.

To detect a horizontal-lines relation using snapping

• Use horizontal-line(Ox) snapping to detect a horizontal-lines relation for the line or axis you are drawing and thus snap the line/axis accordingly. For details, see Snapping objects.

Example

note: The parallel and perpendicular relations take precedence over the horizontal-lines relation. For example, when you are drawing a line and its preview is parallel to both the x-axis and another horizontal line, a parallel relation is detected with the other line.

A horizontal line

note: Since every horizontal line relation is defined between a line and the x-axis ( i.e. not another user-drawn object ), when modifying horizontal lines they are not kept parallel to the x-axis: the system only detects but does not set horizontal line relations.