Chapter 9, Problem 9.16P

Figure (a) shows the cross-sectional dimensions for the structural steel section known as $\text{C}10\times 20$ (channel with a nominal depth of 10 in., weighing 201b/ft). The American Institute of Steel Construction Structural Steel Handbook lists the following properties for the cross section: $A=5.88\text{in}{\text{.}}^2,{\bar{I}}_x=78.9\text{in}{\text{.}}^4,$ and ${\bar{I}}_y=2.81\text{in}{\text{.}}^4.$ If two of these channels are welded together as shown in Fig. (b), find ${\bar{I}}_x$ and ${\bar{I}}_y$ for the resulting cross section.