Determine the inelastic zone lengths at A$,$ B$,$ and C for the fixed$-$end beam of the uniform I section

shown in Figure when $($a$)$ the section at A becomes fully plastic and $($b$)$ when sections at A$,$ B$,$ and C

all become fully plastic. Plastic moment for the beam Mp$=360$ kNm$.$ Shape factor S$=1\mathrm{.}2.$ Assume a

linear moment$-$curvature relationship up to plastic moment.