$C_{1}=\frac{2 \pi \epsilon_{0}}{\ln \left(\frac{2 R}{R}\right)}=\frac{2 \pi \epsilon_{0}}{\ln 2}$
$C_{2}=\frac{2 \pi \epsilon_{0}}{\ln \left(\frac{2 \sqrt{2 R}}{2 R}\right)}=\frac{4 \pi \epsilon_{0}}{\ln 2}$
$C_{e q}=C_{1}+C_{2}=\frac{2 \pi \epsilon_{0}}{l n 2}+\frac{4 \pi \epsilon_{0}}{l n 2}=\frac{6 \pi \epsilon_{0}}{l n 2}$




