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 θ. the area of the opening may be expressed as the function: a(θ) = 16 sin θ ⋅ (cos θ + 1) . if θ = 30°, what is the area of the opening?
a) 14. 9 in²
b) 16. 0 in²
c) 19. 3 in²
d) 20. 8 in²