A steel column used in a college recreation center are 16.75 m long and are formed by

Question:

A steel column used in a college recreation center are 16.75 m long and are formed by welding three wide-flange sections (see figure). The columns are pin-supported at the ends and may buckle in any direction.
Calculate the allowable load Pallow for one column, assuming E = 200 GPa and (Y = 250 MPa.