• m∠ a = _____

m∠ d + m∠ a = 180°

70° - 70° + m∠ a = 180° - 70°

m∠ a = 110°

• m∠ b = ______

m∠ d + m∠ b = 180°

70° - 70° + m∠ b = 180° - 70°

m∠ b = 110°

• m∠ c = _____

m∠ a + m∠ c = 180°

110 - m∠ c = 180° - 110°

m∠ c = 70°