shapearea.java

非常好的JAVA学习资料

public class Shapearea    
{ public double area(float r)
  { return Math.PI*r*r;} 
  public double area(float a,float b)
  { return a*b;}
  public double area(float a,float b,float c)
  {float d;
   d=(a+b+c)/2; 
   return Math.sqrt(d*(d-a)*(d-b)*(d-c));}
 public static void main(String args[])
 {Shapearea sh=new Shapearea();
  System.out.println("The area of circle    :  "+sh.area(3));
  System.out.println("The area of rectangle :  "+sh.area(7,4));
  System.out.println("The area of triangle  :  "+sh.area(3,4,5));}
}