Your answer is going to be 
23% :)
 
        
        
        
Answer:
ASA
Step-by-step explanation:
You can show the angles at either end of segment BC in triangles MBC and LCB are congruent, so you have two angles and the segment between. The appropriate theorem in such a case is ASA.
 
        
             
        
        
        
Supplementary angles
x+20+5x+10=180
6x+30=180
6x=150
x=25
        
                    
             
        
        
        
Answer: 15.9
Step-by-step explanation:
 
        
             
        
        
        
Answer:
exterior because it's an obtuse triangle. 
Step-by-step explanation: