How to draw a polygon
Select the polygon tool from the tool bar. Click
the left mouse button where you want the first node of the polygon.
Without releasing the button, drag the mouse to the point where
you want the second node, then release the button. Click the left
mouse button where you want the next node and release the button.
Click and release the left mouse button where you want the next
node, and the next, and so on. When you come to the last node,
double click the left mouse button.
To draw a closed polygon, double click on the first
node, as the last node.
How to add or delete nodes from an existing polygon
You can insert nodes, delete nodes, or close or open
a polygon using the context menu. To insert a node first select
the polygon. Make sure the selection tool is selected on the tool bar.
Then using the right mouse button, click on the polygon where
you want to insert a node. A context menu will appear. Choose
Insert Node from the context menu.
You can delete a node
by clicking the right mouse button on the node you want to delete
and then choosing Delete Node from the context menu.
How to close an open polygon
You can close or open a polygon by choosing Close from the
context menu.