2.2.13.1.1 Straight Line Objects

End Pt 1: For Straight Lines the object has a starting position (or first point) - altering this value causes the whole object to move relative to the layout origin.
End Pt 2: Straight Lines have a second point, altering this, moves just that end of the line, altering its length as needed.
Angle: Straight Lines have an angle - this is the angle between the two points, altering this moves the ends so as to respect the Lock control setting.
Length: The Length control can add to the start or end or both of a Line object depending on the setting of the Lock control setting.