For this we need to use sinus law because there is no right angle in the observed triangle to solve it in some easier way.
[tex] \frac{a}{sin( \alpha )} = \frac{b}{sin( \beta )} [/tex]
where a is height of the water tower, b is length from point of view till bottom of the tower, [tex] \alpha [/tex] is the angle from point of view and [tex] \beta [/tex] is angle opposite from b.
We use this law to calculate beta angle.
[tex]sin( \beta ) = \frac{b}{a} *sin( \alpha )[/tex]
[tex]sin( \beta ) = 0.742[/tex]
[tex] \beta = 47,924[/tex]
Now we observe different angle. Bottom of the hill-top of the tower-point of view. We calculate angle at point of view (notice how it is different than previous one).
180-90-47.924 = 42.076
At last, the hill inclination is:
42.076 - 8 = 34.076 = 34.1
