Answer:
Well a shape reflecting across the x axis will look like some thing in the image below.
Look at both images.
Answer:

Step-by-step explanation:
The ratio of a circumference to its diameter is equal to an irrational number, called pi, roughly equal to 3.14, denoted by symbol

Therefore, knowing the diameter d, the circumference is equal to d*π
D. 64, because 8x16 is 128, and that divided by 2 is 64. ;)