CUET Preparation Today
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 : |
30° 60° 90° 120° |
30° |
$∑a=6\frac{∑\sin A}{3}⇒∑a=2∑\sin A$ $⇒K∑\sin A=2∑\sin A⇒K=2$ Now $\frac{a}{\sin A}=2⇒A=30°$ |
