Method 1.
Look at the picture 1.
We have:

Picture 2.

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Method 2. (Picture 3)
ΔLOM and ΔMON are isosceles triangles. Therefore the two angles opposite the legs are equal.
The sum of the internal angles in each triangle is 180°. Thereofre in ΔLMN we have:


 
        
             
        
        
        
You have to multiply both top and bottom numbers by the same number so 2 equivalent ones would be 30/14 and 45/21.
 
        
                    
             
        
        
        
If you are going to get a "B" then NO!
        
                    
             
        
        
        
Take a better pic and I might be able too