examples of tail shapes
Moving and fixed surfaces that are located at the tail of the aircraft for steering and stabilizing it.
T-tail unit 
Tail unit made up of two horizontal components attached at the top of a vertical component.
triple tail unit 
Tail unit made up of three vertical components attached to a horizontal component.
fin-mounted tail unit 
Tail unit made up of two horizontal components attached halfway up a vertical component.
fuselage mounted tail unit 
Tail unit made up of two horizontal components attached to the tail.