tx.java

一个求圆

public class TX{                                           //定义了类TX，作为外部类
      double l,s;
      interface jj{                                        //定义了借口jj
           public double circle();
           public double area();
           public void output();
}
      public class SJX implements jj{                      //定义了内部类SJX，用于求解三角形的周长和面积
           double a,b,c,d,e;
           public SJX(double x,double y,double z){
                  a=x;
                  b=y;
                  c=z;
}
           public double circle(){
                  l=a+b+c;
                  return l;}
           public double area(){
                  d=l/2;
                  e=d*(d-a)*(d-b)*(d-c);
                  s=Math.sqrt(e);
                  return s;
}
           public void output(){
                  System.out.println("三角形的周长是："+this.circle());
                  System.out.println("三角形的面积是:"+this.area()); }
}
      public class JX implements jj{                       //定义了内部类JX，用于求解矩形的周长和面积
           double m,n;
           public JX(double x,double y){
                  m=x;
                  n=y;
}
           public double circle(){
                  l=(m+n)*2;
                  return l;}
           public double area(){
                  s=m*n;
                  return s;
}
           public void output(){
                  System.out.println("矩形的周长是:"+this.circle());
                  System.out.println("矩形的面积是:"+this.area()); }
}
      public class YX implements jj{                      //定义了内部类YX，用于求解圆形的周长和面积
           double r;
           final double PI=3.14;
           public YX(double x){
                  r=x;
}
           public double circle(){
                  l=2*PI*r;
                  return l;}
           public double area(){
                  s=PI*r*r;
                  return s;
}
           public void output(){
                  System.out.println("圆形的周长是:"+this.circle());
                  System.out.println("圆形的面积是:"+this.area()); }
}
     public class ZX implements jj{                      //定义了内部类ZX，用于求解直线的周长和面积
           double x1,x2,y1,y2,i,j;
           public ZX(double x,double y,double z,double w){
                  x1=x;
                  x2=y;
                  y1=z;
                  y2=w;
}
           public double circle(){
                  i=(x1-x2)*(x1-x2);
                  j=(y1-y2)*(y1-y2);
                  l=Math.sqrt(i+j);
                  return l;}
           public double area(){
                  s=-1;
                  return s;
           }

           public void output(){
                  System.out.println("直线的周长是:"+this.circle());
                  System.out.println("直线的面积是:"+this.area());
                }
}
}