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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
\[\frac{1}{\sqrt{2}}\]
Solution
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`
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