using System;

public class Rectangle: Shape

{

    //fields

    public double length;

    public double width;

    //step 2: 

    public double getArea(){

    return length*width;

    }

}

public class Triangle: Shape 

{

    //fields 

    public double bases; 

    public double height;

    //step 2

    public double getArea(){

    return bases*height;

    }

    string getString(){

    return "katie";

    }

}

// Start here: the interface

interface Shape

{

    double getArea();

}

​

interface toString 

{

string toString();

}

​

​