个回答

• 会飞的小猪崽儿

  2017-03-04 18:27:33

  //抽象类

  public abstract class Shape {

  public abstract void perimeter();

  public abstract void area();

  }

  //矩形类

  public class Rectangle extends Shape {

  public double height;

  public double width;

  @Override

  public void perimeter() {

  // TODO Auto-generated method stub

  System.out.println("矩形的周长是："+(height+width)*2);

  }

  @Override

  public void area() {

  // TODO Auto-generated method stub

  System.out.println("矩形的面积是："+height*width);

  }

  }
  

  //圆形类

  public class Circle extends Shape {

  public double radius;

  public final double PI=Math.PI;

  @Override

  public void perimeter() {

  System.out.println("圆形的周长是："+2*PI*radius);

  }

  @Override

  public void area() {

  System.out.println("圆形的面积是："+PI*radius*radius);

  }

  }

  //测试类

  import java.util.Scanner;

  public class Test {

       public static void main(String[] args) {

       Scanner input=new Scanner(System.in);

      

      System.out.println("请输入矩形的长和宽：");

       Rectangle rec=new Rectangle();

       System.out.print("长：");

       rec.height=input.nextDouble();

       System.out.print("宽：");

       rec.width=input.nextDouble();

       rec.perimeter();

       rec.area();

      

       System.out.println("请输入圆的半径：");

       Circle cir=new Circle();

       cir.radius=input.nextDouble();

       cir.perimeter();

       cir.area();

      

       input.close();

       }

  }

  这是我自己写，就是对结果的精度没有做处理

  5