This deletes the corner where the first helper is located. And since the first edge has changed, it will also relocate the helpers
See also: Create objects | Headsup CommandLine | Rotate Precisely | Free rotation | Delete | Free Dragging | Delete a corner | Add a corner | Shift a corner | Undo | Redo | Precise move | Stretch Side | Extrude Side | Edge Type | Step Size | Advanced methods for setting attributes of an object | Searching Objects and Classes