Hey! I’m not sure what you’re needing help on but if it’s an answer i’m pretty sure the answer would be - 180 (hx)
        
             
        
        
        
Simple.....

All you have to do is simplify the radical by breaking the radicand up into a product of known factors.
Thus, your answer.
 
        
        
        
Answer:
28.9
Step-by-step explanation:
Using cosine, we get the equation cos(21)=x/31. Solving cos(21), we get about 0.933. Then we multiply by 31 to get about 28.9.