Check the picture below.
running a perpendicular line like so from the right-angle, makes three similar triangles, the large, containing the smaller ones, and a medium and a small one.  Now, using proportions, you can just  use there, the medium and smalle to get "x".
 
        
        
        
Answer:
x = 50
Step-by-step explanation:
101 + (x + 29) = 180
130 + x = 180
x = 180 - 130
x = 50
 
        
                    
             
        
        
        
This is 1:25 (C) 
Explanation:
        
             
        
        
        
Answer:
4. SR= 17 (opposite angle of parallogram are equal)