In the given figure, AB || CD. Find the value of x.
Draw EF ∥ AB ∥ CD.
EF∥CD and CE is the transversal.
Then,
∠ECD + ∠CEF = 180° Angles on the same side of a transversal line are supplementary
⇒ 130° + ∠CEF = 180°
⇒ ∠CEF = 50°
Again, EF∥AB and AE is the transversal.
Then,
∠BAE + ∠AEF = 180° Angles on the same side of a transversal line are supplementary
⇒ x° + 20° + 50° = 180°
∠AEF = ∠AEC + ∠CEF
⇒ x° + 70° = 180°
⇒ x° = 110°
⇒ x = 110