Question

If cos−1α+cos−1β+cos−1γ=3π,then α(β+γ)+β(γ+α)+γ(α+β) equals(A)0(B)1(C)6(D)12

Answer 1

Here Is Your Answer:-=====================⤵

Taking A as centre, draw a circle of radius 4 cm and taking B

Construct tangents to each circle from the centre of the other circle.