In a ∆ABC, the internal bisectors of the angle B and the angle C intersect at an angle of 105°. What is the value of the angle A?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 30°.
In a triangle ABC, I is an incentre then
∠BIC = 90 + (1/2)∠A ----- (1)
Using equation (1), we get
⇒ 105 = 90 + (1/2)∠A
⇒ 15 = (1/2)∠A
⇒ ∠A = 30