Drawing Lines
Tracing a line
To trace a line:
1. In the object inserting bar, click
Graphical object 
.
2. In the drop-down menu, select Line.
3. In the diagram, click where you want the line to begin and drag the cursor while holding your click down.
4. Release the mouse button where you want the line to end.
The line is created as a straight line with a handle at each end.
5. (If needed) Modify its style with the shape editing bar of the diagram.
Creating a joint
You can segment a line to create a jagged line for example.
To segment a line:
1. Select the line.
2. Position the cursor on the line.
3. Press the <Ctrl> key.
The cursor turns into a + shape.
4. Holding down the <Ctrl> key, click and move the cursor to where you want to segment the line.
A joint represented by a handle is added.
5. Holding down the <Ctrl> key, click and move your cursor outside the line to break it.
6. Release the <Ctrl> key.
You can perform this operation as many times as you want. You can then drag the joints to modify the shape of the line.
Deleting a joint
To delete a joint (except at both ends):

Right-click the joint and select
Delete Joint.
The joint is deleted.

Alternative: double-click the joint.
Delete all joints
You can turn a broken line into a straight line.
To delete all the joints:

Right-click a joint and select
Delete all Joints.
The line turns straight.