Calculate Area of Rectangle and Triangle using Single Inheritance

class Rectangle 
            { 
                int l,b; 
                Rectangle(int x,int y) 
                  { 
                     l=x; 
                     b=y; 
                  } 
                     int getRectangle() 
                      { 
                         return l*b; 
                      } 
            } 
                    class Triangle extends Rectangle 
                       { 
                           float a; 
                           Triangle(int v,int u) 
                              { 
                                  super(u,v); 
                              } 
                                  float getTriangle() 
                                     { 
                                         a=(float)l/2*l*b; 
                                         return (a); 
                                     } 
                      } 
                              class RectangleTriangle 
                                  { 
                                      public static void main(String args[]) 
                                           { 
                                               Triangle m=new Triangle(500,80); 
                                               System.out.println("Area of Rectangle is : " +m.getRectangle()); 
                                               System.out.println("Area of Triangle is : "+m.getTriangle()); 
                                           } 
                                  }