B. 3 to 5 & D. 7 to 12. because unchanging, in this case, means not moving.(or the flat lines)
The greatest common factor is 
Explanation:
The given expression is 
We need to determine the greatest common factor of the given expression.
The greatest common factor of two numbers is the largest number of the two numbers that divides them both.
Hence, from the given expression, let us common out the highest factor that divides the two numbers.
Thus, we have,

Thus, the largest number that divides both the terms is 
Hence, the greatest common factor of the given expression is 
this is when its solved: r=4, s=3}
That's a 240 degree sector of a 9 inch radius circle. The whole circle has area πr² and we want 240/360 of it.
A = (240/360) π (9²) = 54 π
Answer: 54 π square inches
That's the exact answer. An approximation is
169.646 square inches