In the given figure, a || b and c || d. If ∠1=75∘, what is the measure of ∠3?
105∘
Given a || b and c || d and ∠1=75∘
Since, a || b,
∠1=∠2 =75∘ (corresponding angles are equal)
Also c || d,
⇒∠2+∠3=180∘ [sum of co-interior angles is 180]
∴∠3=180∘−75∘ =105∘