I’m not sure but since no one else commented I would think it’s D, I think you take the first number like 6 for a and subtract the first number for b like 3
Answer:
x = 22
Step-by-step explanation:
x = 7 + 15
x = 22
Equating the formula (d is the diameter)

d^2/4 = 132.7
d^2 = 132.7*4/

d =

d = 13.0017147331
d= 13cm
The first question is c i believe, I dont have time to answer the others