Answer with explanation:
→If , AB ║ CD and AD ║ BC
∠2 + ∠ D=180°----------(1)
→DA is a line.So, By linear pair
∠1 + ∠ 2=180°------------(2)
Equating (1) and (2)
∠1 + ∠ 2=∠2 + ∠D
Cancelling , ∠2 from both sides, gives
→∠1=∠D, is true statement.
You can also write Directly that, (∠1 and ∠D), and (∠3 and∠B), are corresponding angles, as lines are parallel,then corresponding angles are equal.