Answer:
C = 50.24
A = 7,925.540864 (Round to whatever you want)
Step-by-step explanation:
c = 2πr
c = 2(3.14)(8)
c= 50.24
A = πr^2
A = (3.14)(50.24)^2
A = 7,925.540864
Let's build the equation counting how many x's and 1's are there on each side.
On the left hand side we have 5x's and 8 1's, for a total of 
On the left hand side we have 3x's and 10 1's, for a total of 
So, the equation we want to solve is

Subtract 3x from both sides:

Subtract 8 from both sides:

Divide both sides by 2:

The answer for the greatest common factor of 12 and 16 is 4