A rain gutter is to be constructed of aluminum sheets 12 inches wide. After marking off a length of 4 inches from each edge, this length is bent up at an angle . The area A of the opening may be expressed as the function: A() = 16 sin (cos + 1). If = 60, what is the area of the opening? (6 points)

1.2 in²

7.9 in²

16.3 in²

20.8 in²