Question

If angles A, B, C to a ∆ABC from an increasing AP, then sin B = 

Options

• \[\frac{1}{2}\]

• \[\frac{\sqrt{3}}{2}\]

• 1

• \[\frac{1}{\sqrt{2}}\]

Answer 1

Let the angles of a triangle Δ ABC be (a-d), (a),(a+d)espectively which constitute an A.P.As we know that sum of all the three angles of a triangle is 180°. so, (a-d)+a(a+d)=180° 

So, a =60° 

Therefore,  ∠ B= 60° 

Hence, `sin ∠B= sqrt3/2`