Answer
$2.646\times 10^{-4}m^2$
Work Step by Step
The force in the left vertical support column is $44100N$, in compression. We want a steel column that can handle three times that or $132300N$. Steel has a compressive strength of $500\times10^6N/m^2$. Use this to find the area.
$$\frac{F}{A}=\frac{132300N}{A}=500\times 10^6 N/m^2$$
$$A=\frac{132300N}{500\times10^6 N/m^2}=2.646\times10^{-4}m^2$$
