Common class rectangle {

Private int width;

Private int height;

Common rectangle (int width, int height) (

This.width = width;

This.height = height;

}

Common void length () {

int length = 2 *(this . width+this . height)；

System.out.println ("circumference:"+length);

}

Public vacant area () {

int area = this . width * this . height；

system . out . println(" area:"+area)；

}

}

//Java file 2: javatest

Public class JavaTest {

Public static void main(String[] args) {

Rectangle r = new rectangle (20,10);

r . length()；

r . area()；

}

}

Put these two files together and run file 2 JavaTest for debugging.