Answer:  The correct option is
(E) 70.
Step-by-step explanation:  We are given to find the number of  triangles and quadrilaterals altogether that can be formed using the vertices of a 7-sided regular polygon.
To form a triangle, we need any 3 vertices of the 7-sided regular polygon. So, the number of triangles that can be formed is

Also, to form a quadrilateral, we need any 4 vertices of the 7-sided regular polygon. So, the number of quadrilateral that can be formed is

Therefore, the total number of triangles and quadrilaterals is

Thus, option (E) is CORRECT.
 
        
             
        
        
        
Answer:  D.  7^11
Reason:
The rule we use is 
When multiplying exponentials of the same base, we add the exponents.
The exponents 5 and 6 add to 5+6 = 11
So,

The base stays the same the entire time.
 
        
                    
             
        
        
        
Answer:
y=55 degrees x=125 degrees
Step-by-step explanation: