为什么这里的F不能被调用？

Question

class Area{ double F(double f){ return 3.14*f*f; } double G(double X,double Y){ return X+Y; }}class Circle extends Area{ double F(double f){ return 2*3.14*f; }}public class TestArea { double lenght,sum; Circle yuan=new Circle(); //yuan.F(5.0);}

Answer 1

在妹涵数里面new, 然后调用