Please read UseCodeTags (<-click). By following the directions given, your code will be easier to read, thus increasing your chances of getting a good answer.
As for your issue, the error message you get is pretty straightforward. You are trying to print the value of variable area but you haven't declared it. However, you can get an area of the rectangle by invoking area() method on an instance of the class representing a rectangle. The method is invoked as: classInstance.methodName().