When a polygon is selected the entity handles for all of its segments are displayed. The editing choices are to either, modify the properties using the Properties Explorer or the Ribbon, or to move one of the entity handles.
Each line segment has three entity handles, one at each end (blue) and one at its midpoint (red). Move the cursor over any of the handles and its colour changes to yellow then simply click to select it. If selected the major handle (red) attaches the whole polygon to the cursor allowing it to be moved to a new position and clicked into place using any of the snaps and input options If any of the minor handles are selected then they can be dragged to new positions and clicked into place using any of the snaps and input options. The two attached lines segments are updated accordingly.
A polygon can be exploded into individual lines and arcs if required.