$1-$A column with cross section shown in this figure. The length of the structure is $2\mathrm{.}8$ m and Young's modulus is $70$Gpa.

A$)$ Find slenderness ratio with respect to axis of buckling if the column has pin for both edges.

B$)$ If boundary condition of the column is pinned$/$fixed and yield stress is $230$ Mpa $,$ find maximum allowable force that can be applied on the column.

C$)$ For different case, consider boundary condition of the column is pinned$/$pinned and there is an axial load of $250$ KN applied on the structure with eccentricity of $1\mathrm{.}5$ mm $($See figure $2).$ Determine maximum compression of the column. $($The length of the column is the same with parts A and B$)$

Higure $1-$Parts A and B