extends作业三

朱雀 2022-06-07 08:08 158阅读 0赞

public class 测试 {
        public static void main(String[] args) {
            Rectangle r=new Rectangle(3,4);
            System.out.println("长=4，宽=3的矩形周长="+r.perimeter());
    
            Triangle t=new Triangle();
            System.out.println( "边分别是3,4,5的三边形周长是：");
            t.perimeter(3, 4, 5);       
        }
    }

public class Rectangle extends Shape { 
        private double a;
        private double b;
    
        public Rectangle( double a, double b) {
            super();
            this.a = a;
            this.b = b;     
        }
        @Override
        public double perimeter(){
            double perimeter;
            perimeter=(a+b)*2;
            return perimeter;
        }
        public double area(){
            double area;
            area=a*b;
            return area;
        }
    }

public class Shape { 
        private double perimeter;
        private double area;
        public Shape(double perimeter, double area) {
            super();
            this.perimeter = perimeter;
            this.area = area;   
        }
        public Shape() {
            super();
        }
        //抽象一个周长方法
         public  double perimeter(){
            return perimeter;
            }
        //抽象一个面积方法
         public  double area(){
                return area;
            }
        }

public class Triangle extends Shape { 
        private double b;
        private double c;
        private double d;
        public Triangle( double b, double c, double d) {
            super();
            this.b = b;
            this.c = c;
            this.d = d;
        }
        public Triangle() {
    
        }
        //周长
         public void
         perimeter (double b,double c,double d) {
             if(b+c>d&&(b-c)<d) {
                 double perimeter ;
                 System.out.println(perimeter =b+c+d);       
            }else {
                System.out.println("这不是三角形");   
            }        
         }
    }