\(\displaystyle{b}^{{2}}={a}^{{2}}+{c}^{{2}}-{2}{a}{c}{\cos{{B}}}\)

\(\displaystyle{b}^{{2}}={5}^{{2}}+{3}^{{2}}-{2}{\left({5}\right)}{\left({3}\right)}{\cos{{92}}}°\)

\(\displaystyle{b}^{{2}}={34}-{30}{\cos{{92}}}°\)

\(\displaystyle{b}=\sqrt{{{34}-{30}{\cos{{92}}}°}}\)

b ~ 5.92