Drawing an Edge <Back
Click the Edge , Arc , or Bezier buttons in the toolbar, then drag out the edge end to end. Like faces, edges are drawn on existing objects, or on the standard plane that is facing the users view. Holding down Shift while dragging will constrain the angle to a multiple of 45 degrees, and holding down Ctrl will temporarily disable snapping to grid.
You can start on an existing point (it will highlight when you move close) and end on an existing point. This is important for making a closed chain of edges for converting into a face later (by grouping and making a face)
For arcs and Beziers, you draw approximately in freehand the endpoints, centre and control points can be changed later. Select the edge to show them.
Note: if you just want to round corners on a face, that is more easily done by drawing the face first and selecting Round Corners from the right-click menu. You can round one or all. The radius is set in Preferences.
These are like normal edges, except that they do not form faces, and their dimensions are always shown by default. They are used to help with layout.
Making a Face from Edges
Draw a closed set of edges that connect end to end. Then right-click one and select Group Connected Edges, to collect them into a group. Then select Make Face to create the face.