What is the area cleaned by the two windshield wipers on my car? 

Here are the (approximate) particulars; see the figure on the left: The area in question is shown in light yellow.  The length of each rubber wiper, BD and DE, is 2 feet, the total length of each wiper arm, AD and CE, is 2ft 6in long, the central axes of the two wipers, A and C, are located 2ft apart, the angles ECF and CAG swept out by each wiper is 100°.  Assume that the bottom edges, AD and CE, of the areas swept out by each of the two individual wipers are parallel and that the glass is flat.