Add, Remove, and Hide Auxiliary Lines
Add / Remove Auxiliary Line (Red Line)
Hover the mouse over the position where you need to add auxiliary lines.
Hover the mouse over the auxiliary line near the ruler where you will see " x ", click it to delete.
Hide Auxiliary Lines
The auxiliary line can be hidden with the ruler, you need to turn off the "Ruler" in "More" - "Preferences" in the upper right corner of the editing area.