Consider this double channel section $($which is doubly symmetric$)$ shown below:

The flange width $\backslash ($ b $\backslash )$ is $79$ mm

The section height h is $194$ mm

The web thickness $\backslash (\backslash$mathrm$\{$t$\}\_\{\backslash$mathrm$\{$w$\}\}\backslash )$ is $10\mathrm{.}2$ mm

The flange thickness $\backslash (\backslash$mathrm$\{$t$\}\_\{\backslash$mathrm$\{$f$\}\}\backslash )$ is $25\mathrm{.}9$ mm

The gap between the channel sections d is $36\mathrm{.}7$ mm

Calculate:

a$)$ The second moment of area, according to $\backslash ($ x $\backslash )-\backslash ($ x $\backslash )$ axis, $\backslash (\backslash$mathrm$\{$I$\}\_\{\backslash$mathrm$\{$xx$\}\}\backslash ),$ in $\backslash (\backslash$mathrm$\{$mm$\}^\{4\}\backslash )$