Answer:
Step-by-step explanation: to find circumference, u do 2*pi*radius or pi times diameter
Answer: It means to multiply
I think it is D hope it works
Y = 16.14z ; the constant of proportionality is 16.14. It is called constant of proportionality because it never changes. It remains constant or the same. Whatever the value of z is, y is directly proportional to z by the rate of the constant of proportionality.