Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Inverse Trigonometric Functions

Question:

The perimeter of a triangle ABC is 6 times the arithmetic mean of the sines of its angles. If the side a is 1, then ∠A is :

Options:

30°

60°

90°

120°

Correct Answer:

30°

Explanation:

$∑a=6\frac{∑\sin A}{3}⇒∑a=2∑\sin A$

$⇒K∑\sin A=2∑\sin A⇒K=2$

Now $\frac{a}{\sin A}=2⇒A=30°$