The first and last choices are the only ones whose angles total 180 degrees, so they're the only possible triangles.
        
                    
             
        
        
        
Answer:
R ≈ 8.31
Step-by-step explanation:
Filling in the given values ...
... pV = nRT
... 2·4.155 = 1·R·1
... 8.31 = R
 
        
             
        
        
        
Answer:
D
Step-by-step explanation:
 
        
                    
             
        
        
        
2.Alternate Interior angles theorem.
They given angles are alternate and interior when compared to each other, so they are congruent.  
3 Vertical angles theorem.
The two angles are vertical angles and are not congruent. 
4 Angle-Angle Similarity Postulate. 
Because there are two corresponding angles that are congruent they are similar triangles by the angle-anlge similarity postulate.