using System;
// 2nd, come here for an example class that is "implementing" the interface below
public class Rectangle : Shape
{
// fields and properties
public double length;
public double width;
//step 2:
public double getArea()
return length* width;
}
public class Triangle : Shape
public double bases;
public double height;
return (bases*height)/2;
string getString()
return "string";
// Start here: the interface
interface Shape
double getArea();