Respuesta :

Answer:

            m∠ABC = 30°

Step-by-step explanation:

m∠BAD = 0.5m∠BCD = 0.5•126° = 63°

The  angles in quadriteral add to 360°, so:

m∠ABC + m∠BAC + m∠ACD + reflex m∠BCD = 360°

m∠ABC + 63° + 33° + (360° - 126°) = 360°

m∠ABC + 96° - 126° = 0

m∠ABC = 30°