3) d) e) f)

Angle d and the 12° angle are subtended by the same arc, hence angle d = 12°. The sum of the angles in the triangle is 180°. Therefore e + 12 + 24 = 180 => e = 180 - 36 = 144°. Angle f is subtended by the same chord as angle e. Therefore, angle f = e/2, so angle f = 144/2 = 72°. Answer: d = 12°, e = 144°, f = 72°