Question:
Which pair of lines in the below fig. is parallel? Give reasons.
Solution:
∠A + ∠B = 115 + 65 = 180°
Therefore, AB ∥ BC [As sum of co interior angles are supplementary]
∠B + ∠C = 65 + 115 = 180°
Therefore, AB ∥ CD (As sum of interior angles are supplementary]