Answer:
if I am guessing this is trigonometry
First is to look at what sides you have in which you have the legs. This means you can use tangent. how ever you need to use arctangent or
tan^-1 to find the angle.
the way you set this up in your calculator is tan^-1(8.4÷15.2). plus be sure it's on Deg not Rad.
This leaves the answer if 28.9°
I hope this helps.