做一个简单的矩形面积计算器，要求你输入长和宽就可以计算出其面积。- Create a class Rectangle (and store it in a file called Rectangle.java)





It should have two instance variables l (the rectangle’s length) and w (the rectangle’s width).



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



Create a main() method in the same class for testing purposes. In the main() method, create one

rectangle with the dimensions (l,w)=(8,5), and another rectangle with the dimensions

(l,w)=(9,9). Call your area method on each rectangle and print the corresponding result.