package zuoye8;

public abstract class Shape {

	private double zhouchang ;

	private double mianji ;

	public Shape(double zhouchang, double mianji) {

		super();

		this.zhouchang = zhouchang;

		this.mianji = mianji;

	}

	public Shape() {

		super();

	}

	//抽象一个周长方法

	 public  double zhouchang ()

	 {

		return zhouchang;}

}

package zuoye8;

public class Juxing extends Shape {

	private double c;

	private double d;

	public Juxing( double c, double d) {

		super();

		this.c = c;

		this.d = d;

	}

	@Override

	public double zhouchang() {

		double zhouchang ;

		zhouchang =(c+d)*2;

		return zhouchang ;

	}

}

package zuoye8;

public class Sanjaio extends Shape {

	//三角形三边属性

	private double a;

	private double b;

	private double c;

	public Sanjaio( double a, double b, double c) {

		super();

		this.a = a;

		this.b = b;

		this.c = c;

	}

	public Sanjaio() {

	}

	//周长

	 public void

	 zhouchang (double a,double b,double c)

	 {

		 if(a+b>c&&Math.abs(a-b)<c)//绝对值，保证是正整数

			{

			 double zhouchang ;

			 System.out.println(zhouchang =a+b+c);

			}

			else

			{

				System.out.println("这不是三角形");

			}

	 }

}

package zuoye8;

public class E {

	public static void main(String[] args) {

		Juxing j=new Juxing(3,4);

		System.out.println("长=4，宽=3的矩形周长="+j.zhouchang());

		Sanjaio s=new Sanjaio();

		System.out.println( "边分别是3,4,5的三边形周长是：");

		s.zhouchang(3, 4, 5);

		s.zhouchang(3,1,5);

	}

}