Current Attempt in Progress

A solid cylinder of radius $r_1=2\mathrm{.}6cm,$ length $h_1=4\mathrm{.}1cm,$ emissivity $0\mathrm{.}73,$ and temperature $29C$ is suspended in an environment of temperature $64C.($a$)$ What is the cylinder's net thermal radiation transfer rate $P_1?($b$)$ If the cylinder is stretched until its radius is $r_2=0\mathrm{.}59cm,$ its net thermal radiation transfer rate becomes $P_2.$ What is the ratio $\frac{P_2}{P_1}?$