There are a few things that could be the problem.
My first guess is that the class is actually a Rectangle instead of a rectangle.
Second, the Rectangle class might not have a zero parameter constructor. It might only have a constructor of Rectangle(int length, int width).
Third, from your post, unless you didn't cut and paste, there is a typo with the constructor found by this error: symbol:constructor retcangle().
Regards,
Nate