Respuesta :

In this situation you would use cos 
which is adjacent over hypotenuse 
so I take the cos50 and have it equal to 17 / x
 cos(50)= 17/x 
which is the same as ...
17 divided by cos(50) =x 
x=26.44730506
which rounds to 26.45 
So your answer would be A)

I hope everything makes sense, enjoy!