Answer:the nth term of the sequence, Tn= -3n +12
Step-by-step explanation:
 The nth term of an arithmetic progression is given as
Tn=  a+ (n-1) d
 where a= first term 
and d = common difference
 In this sequence, 9, 6 ,3 ,0, -3, -6 we can see that  the number is decreasing by 3
 The first term, a= 9 
and common difference, d = -3
 using our formulae
Tn=  a+ (n-1) d
Tn= 9 + ( n-1) -3
Tn=9- 3n+ 3
Tn= -3n +12
 
        
             
        
        
        
For this case we have by definition, that the total surface area of a regular pyramid with a square base is given by:

Where:
p: It is the perimeter of the base
S: It's the inclination
 It is the area of the base
 It is the area of the base
Substituting:

ANswer:
Option B
 
        
             
        
        
        
40/3. You mutiply top and bottom straight across, then simplify.