Respuesta :
a = 70° [because vertically opposite angles are equal.]
c + 150° = 180° [They are linear pair]
=> c = 180° - 150°
=> c = 30°
a+b+c= 180° [Sum of all angles of a triangle=180°]
=> 70° + b + 30° = 180°
=> 100° + b = 180°
=> b = 180° - 100°
=> b = 80°