Are there components of the velocity that cannot be determined by measuring the force?

Aregular polygon has angkes of size 150° each.how many side has the polygon

The rigid beam is supported by the three suspender bars. bars ab and ef are made of aluminum and bar cd is made of steel. if each bar has a cross-sectional area of 450 mm2, determine the maximum value of p if the allowable stress is (σallow)st = 200 mpa for the steel and ( σallow)al = 150 mpa for the aluminum. est = 200 gpa and eal = 70 gpa.

Could someone . i have tried to solve myself but my calculation is off