Constructor Overloading in java

public class ConstructorOverloading{
public static void main(String args[]){
Rectangle rectangle1=new Rectangle(2,4);
int areaInFirstConstructor=rectangle1.first();
System.out.println(" The area of a rectangle in first constructor is :  " + areaInFirstConstructor);
Rectangle rectangle2=new Rectangle(5);
int areaInSecondConstructor=rectangle2.second();
System.out.println(" The area of a rectangle in first constructor is :  " + areaInSecondConstructor);
Rectangle rectangle3=new Rectangle(2.0f);
float areaInThirdConstructor=rectangle3.third();
System.out.println(" The area of a rectangle in first constructor is :  " + areaInThirdConstructor);
Rectangle rectangle4=new Rectangle(3.0f,2.0f);
float areaInFourthConstructor=rectangle4.fourth();
System.out.println(" The area of a rectangle in first constructor is :  " + areaInFourthConstructor);
}
}

class Rectangle{
int l, b;
float p, q;
public Rectangle(int x, int y){
l = x;
b = y;
}
public int first(){
return(l * b);
}
public Rectangle(int x){
l = x;
b = x;
}
public int second(){
return(l * b);
}
public Rectangle(float x){
p = x;
q = x;
}
public float third(){
return(p * q);
}
public Rectangle(float x, float y){
p = x;
q = y;
}
public float fourth(){
return(p * q);
}
}