Edges

Click this tool when you want to edit the edges of polygons. Selected edges are colored.

You can select and edit edges in much the same way as for points.

To select an edge, drag over the edges with the Brush Selection tool, just as you would to select points (or use any other selection tool).
To add edges to the selection, hold down Shift while you select.
To remove edges from the selection, hold down Ctrl/Cmd while you select.
To select all edges, choose Select / Select All.
To deselect all edges, choose Selection / Deselect All or drag the selection tool over an empty space within the Viewport.

You can use the Move, Scale and Rotate tools to edit the selected edges. To delete the selected edges (including their polygons), press Delete.

Tools that can be useful for editing such as the Bevel, Edge Cut and especially the Polygon Pen can be called up via a context menu. To do so, simply right-click on a point. Mac users need to Cmd+click to call up the context menu.