2/3 reciprocal is 3/2, & 8/3 reciprocal is 3/8. The numbers are just filled to find their reciprocal!
Not sure if you wanted answers or explanation on what to do. Ill just do the explanation and if you want the answers just lmk C:
R=1/2 d, and C=pi*2r. So you basically take the given number and plug it into these formulas.
Well I guess and I hope it helped