Answer:
c) 2 pi x
Step-by-step explanation:
The circumference is based on the equations:
C = pi * d where d = diameter
We also know that the radius is half of the diameter as its the length of a line from the centre of the circle while the diameter is the length of two opposite points through the centre of the circle.
This tells us that d = 2r
So we can replace the equation for the circumference with:
C = pi * 2r
An increase of x to the radius would thus mean that the circumference is increased by 2(pi * x), as 2(pi * (r + x) could be used to find the new value of the circumference, which is the same as:
2(pi * r) + 2(pi * x)
So the answer is 2 pi x
