Using the slope concept, it is found that rhe blade's length is of 90 feet.
The slope is given by the vertical change divided by the horizontal change, and it's also the tangent of the angle of depression.
In this problem, the horizontal change is of 440 feet.
At the highest point, the angle is of 38º, hence:
[tex]\tan{38^\circ} = \frac{h_1}{440}[/tex]
[tex]h_1 = 440\tan{38^\circ}[/tex]
[tex]h_1 = 344[/tex]
At the lowetst point, the angle is of 30, hence:
[tex]\tan{30^\circ} = \frac{h_2}{440}[/tex]
[tex]h_2 = 440\tan{30^\circ}[/tex]
[tex]h_2 = 254[/tex]
Hence, the difference is:
[tex]h_2 - h_1 = 344 - 254 = 90[/tex]
The blade's length is of 90 feet.
More can be learned about the slope concept at https://brainly.com/question/18090623
