61父类和子类 uperclass Circle Circle methods Circle data Inheritance Subclass Cylinder Circle methods Circle data Cylinder Methods Cylinder Data Superclass Subclass UML Diagram Circle CⅤ linder radius length getRadius setRadius findArea setlength find Volume6.1 父类和子类 Superclass Circle Circle Methods Circle Data Inheritance Cylinder Circle Methods Cylinder Methods Circle Data Cylinder Data Subclass Circle -radius +getRadius +setRadius +findArea Cylinder -length +getLength +setLength +findVolume Superclass Subclass UML Diagram