1: package interfaces; 3: // Measurable.java 4: // week09 code 5: // a very simple interface to experiment with 6: // See also: 7: // Circle.java 8: // Rectangle.java 9: // MeasuringStuff.java 11: // a class is measurable if 12: public interface Measurable { 14: // it has a method like this (to get an object's area) 15: public double getArea(); 17: // and it has a method like this (to get the object's perimeter) 18: public double getPerimeter(); 20: }