Add Lines

Select a line - see image attached. Click Use
Drag the line with drag and drop. Hover over the defining box until you see a cross.
Use the keyboard arrows to move it around.
Resize it by dragging the margins from the right (see the double-arrow) - to make it shorter or longer
Resize it from the top or bottom to increase its height.
Use Maintain proportions, if needed.
Use search to find a line.

Use the SHAPE properties in the EDIT (right menu) to change color, thickness, transparency
Use Image and Textbox properties to rotate it, change position, height and width, etc