The Line Tool allows you to create vector shapes in the form of lines and arrows.

The basic tool settings are shown in the Tool Options panel above the Image Window. To display the full list of parameters, press the tool icon in the Tool Options panel, or use the F5-key.
You can find general parameters of vector shapes here.
In addition, the following options are available:
Weight (3-100). The parameter specifies the line width.


Arrowheads. Select where the arrows will be located on the line: at the start, at the end.

Arrow Width (3-100). The parameter specifies the width of the arrow.


Arrow Length (3-100). The parameter specifies the length of the arrow.


Concavity (-50..50). The parameter specifies the curvature of the arrowheads.


By holding down the Ctrl key, you can move the shape with the mouse. By holding down the Shift key, you can select multiple shapes.
You can also use shape editing tools.