Answer:
a(n) = 

Step-by-step explanation:
The given expression is in the form of the explicit formula of a geometric sequence.
f(n) = 
Where 'a' = First term of the sequence
r = common ratio
Recursive formula of a geometric sequence is,
a(n) = 
a(n) = 
Where, 
So the recursive formula will be a(n) = 
C obtuse scalene
Source:
http://www.1728.org/triang.htm
Answer: C
Explanation:i got it right on my test