Answer: 10,779 feets
Step-by-step explanation:
From the sketch attached ;
∠POT is the Angle of elevation = 33°
Height of tower = 7000 Feets
Taking the triangle POT
WHERE PT = 7000 Feets (Opposite)
Distance (d) between the bird and plane is the ADJACENT,
NOTE: (BP = OT = d)
Taking the tangent of the angle of elevation;
Tan Θ = opposite / Adjacent
Tan 33° = 7000 / d
Cross multiply
d × 0.6494075 = 7000
d = 7000 / 0.6494075
d = 10779.054 = 10,779 feets