Question

The angles of elevation θ and φ, to an airplane are being continuously monitored at two observation points A and B, which are 3 miles
apart.
Write an equation giving the distance d
between the plane and point B in terms of θ
and φ.

Answer 1

180- φ =angle B

Answer 2

Find angle C = 180- (angle A and angle B)
Use sine law to find d

Answer 3

so what about the 3?

Answer 4

sin (angle c) / 3 = sin (angle A) / d