Consider the equal$-$flange steel section in Figure $4,$ given that h $=1800$mm$,$ b $=500$mm$,$ tw $=20$mm$,$and tf $=50$mm$,$ determine:$($a$)$ The position of neutral axes for bending about the major and minor axes of the section.$($b$)$ The second moment of area and the radius of gyration about both the major and minoraxes of the section.