Answer:
REF.Image
In △ABD
AB=AD
and
In △CBD
CB=CD
As angle opposite to equal
sides are equal, so,
→In △ABD
∠30+∠x+∠x=180
∘
[∵ angle sum property and ∠ABD=∠ADB=∠x]
2∠x=180
∘
−30
∘
∠x=
2
150
∘
∠x=75
∘
→ In △EBD
∠60
∘
+∠y+∠y=180
∘
[(angle sum property) and ∠CBD=∠CDB=∠y ]
2∠y=180
∘
−60
∘
∠y=
2
120
∘
∠y=60
∘
∠ABC=∠ABD−∠CBD
=∠x−∠y
=75
∘
−60
∘
∠ABC=15
∘
Option C is correct
