Answer:
Diameter=35
Explanation:
If your circumstance is 35pi then the formula would be C=35pi and to find that it would have been C=2 pi r. To find the diameter it would be d=c/pi. So it would be d=35pi/pi. The pi's would cancel out and you have 35 as the diameter and 17.5 as the radius
Check:
C=2 pi r
C= 2 pi 17.5
C=35pi ✅
D=2r
D=2(17.5)
D=35✅
I hoped this helped, I am not sure but this is what I think