Question 1171584
.
<pre>

The resultant force is the hypotenuse of the right triangle with the legs 7.5 units (horizontally) and 12 units (vertically).


Use the Pythagorean formula to find its value.


Find the angle "a" of the force vector to horizontal direction from this equation


    tan(a) = {{{12/3.5}}} = 3.428,

    a = arctan(3.428).


Use your calculator.
</pre>

Solved.


Do not forget to post your "THANKS" for my teaching.