berdasarkan nilai disamping, nilai x + y =

sudut sehadap I :
3y + 2y = 180°
5y = 180°
y = 180°/5 = 36°

sudut sehadap II :
3y + x = 180°
3(36°) + x = 180°
108° + x = 180°
x = 180°-108° = 72°

nilai x+y = 36° + 72° = 108° (D)