Let a = 7 , b  = 7, and c = 13. c is always the biggest number.
Acute Triangle is when 

Right Triangle is when 

Obtuse Triangle is when 
 
        
             
        
        
        
Answer:
If you mean getting lower numbers then they are nonequivalent if bigger numbers they are equivalent
Step-by-step explanation:
 
        
                    
             
        
        
        
In a parallelogram the 4 angles need to sum to 360 degrees. There are two sets of identical angles, so one of the other angles would also be 80 degrees.
Now find the other two angles:
 360 - 80 - 80 = 200 degrees
200 degrees / 21 = 100 degrees each.
 The other 3 angles are: 80, 100 and 100
 
        
             
        
        
        
The answer would be 1.577664617x10^18