Illustrate about the single inheritance

During inheritance, superclass feature may by override by a subclass defining that feature with the same name. The overriding features (the same name subclass feature with superclass features) refine and replace the overridden feature (the same name superclass feature).  Now take a look at the diagram given in Figure. In this diagram, Triangle, Square, and Circle classes are inherited from Shape class. This case is the case of single inheritance since one class inherits from only one class.