Here we have to use the trigonometric formula for right-angled triangle.
This is the structure described in the question. We have to find x which is the angle between the wire and the ground.
From the trigonometric formula of right angled triangle we know that
[tex]\sin x=\frac{opposite\text{ side}}{\text{hypotenuse}}[/tex]So
[tex]\sin x=\frac{21}{35}\Rightarrow\sin x=\frac{3}{5}\Rightarrow x=\sin ^{-1}(\frac{3}{5})\Rightarrow x=36.8642[/tex]At the top of the pole the wire will make angle with the pole is
[tex]\cos y=\frac{Adjacent}{\text{Hypotenuse}}\Rightarrow\cos y=\frac{21}{35}\Rightarrow y=\cos ^{-1}(\frac{3}{5})\Rightarrow y=53.1301[/tex]So the wire makes a 53.1301-degree angles with the top of the pole.
