In the given figure, ∠ABC = 81° and ∠ACB = 9°. What is the value of ∠BDC?
Answer & explanation
Correct answer: option 2
⇒ In \(\Delta \)ABC
⇒ ∠ABC + ∠ACB + ∠BAC = 180° (Angle sum property)
⇒ 81° + 9° + ∠BAC = 180°
⇒ ∠BAC = 180° - 90° = 90°
Now,
⇒ ∠BAC = ∠BDC = 90° (angle in same segment)
Therefore, the answer is ∠BDC = 90°.