Parameterized Constructors

class Demo{
    double height;
    double base;
    Demo(double height, double base){
        this.height = height;
        this.base = base;
    }
    double area(){
        return 0.5*base*height;
    }
}
public class Main{
    public static void main(String args[]){
        Demo dm = new Demo(10.0,5.0);
        double res = dm.area();
        System.out.println("The area of a Triangle is: " + res);
    }
}