Answer: Option 'C' is correct.
Step-by-step explanation:
Since we have given that
Distance at which a bird watcher is away from the base of the tree= 45 feet
Length of the tree at the top of which he spots an oriole = 140 feet
As the figure shown below:
In ΔABC,
[tex]\tan\theta=\frac{AB}{AC }\\\\\tan\theta=\frac{140}{45}=\frac{28}{9}\\\\\tan\theta=3.111\\\\\theta=72.12\textdegree=72\textdegree[/tex]
Hence, the angle of elevation from the bird watcher to the oriole will be
[tex]72\textdegree[/tex]
Therefore, Option 'C' is correct.
