抽象类
public abstract class Shape{
public abstract double getArea();
public abstract double getPerimeter();
}
Circle类
public class circle extends Shape{
private double r ;
public Circle(doublic r){
this.r = r;
}
public double getArea(){
double m = Math.PI*r*r;
return m;
}
public double getPerimeter(){
double m = 2*Math.PI*r;
return m;
}
}
Rect类
public class Rect extends Shape{
private double a;
private double b;
public Rect(double a,double b){
this.a = a;
this.b = b;
}
public double getArea(){
double m = a*b;
return m;
}
public double getPerimeter(){
double m = 2*(a+b);
return m;
}
}
测试类
public static void main(String[] args){
Rect r = new Rect(5,4);
double a = r.getArea();
double p = r.getPerimeter();
System.out.println(a);
System.out.println(p);
}
