画出一个矩形 长宽都可自定义 还可以计算其面积-Create a class Rectangle.i) It should have two instance variables l (the rectangle’s length) and w (the rectangle’s width).

ii) It should have one method that calculates the area of the rectangle and returns it to the caller.

iii) Create a main() method in the same class for testing purposes. In the main() method, create one rectangle with the dimensions (l,w)=(8,6), and another rectangle with the dimensions (l,w)=(7,7). Call your area method on each rectangle and print the corresponding result.