Correct option (A)1/4
Explanation:
OB = R
∠AOC = 2A, ∠BOD = A
f = OD = RcosA
L.H.S = a/f + b/g + c/h = a/RcosA + b/RcosB + c/RcosC
PutR = a/2sinA = 2(tanA + tanB + tanC) = 2tanA tanB tanC
R.H.S. = λ(abc/(R3cosAcosBcosB))
Put R = a/2sinA = 8λ tanA tanB tanC
⇒ λ = 1/4