Figure 28-33 shows a current loop $A B C D E F A$ carrying a current $i=3.00 \mathrm{~A}$. The sides of the loop are parallel to the coordinate axes shown, with $A B=20.0 \mathrm{~cm}$, $B C=30.0 \mathrm{~cm}$, and $F A=10.0 \mathrm{~cm}$. In unit-vector notation, what is the magnetic dipole moment of this loop? (Hint: Imagine equal and opposite currents $i$ in the line segment $A D ;$ then treat the two rectangular loops $A B C D A$ and $A D E F A$.)