In the given figure,BAD||EF,∠AEF=55∘and ∠ACB=25∘,find ∠ABC.
ANSWER:
In the given figure, EF || BD and CE is the transversal.
∴ ∠CAD=∠AEF
(Pair of corresponding angles)
⇒∠CAD=55∘
In △ABC,
∠CAD=∠ABC+∠ACB
(Exterior angle of a triangle is equal to the sum of the two interior opposite angles)
⇒ 55∘=∠ABC+25∘
⇒ ∠ABC=55°−25°=30∘
Thus, the measure of ∠ABCis30∘