Two forces lying in the $x-y$ plane are defined by their magnitudes and direction angles, as shown in the figure below. Force vec$(F{)}_1$ has a magnitude $F_1=550N,$ an angle ${}_1=124,$ and acts at point $A=(420,0)mm.$ Force vec$(F{)}_2$ has a magnitude $F_2=980N,$ an angle ${}_2=87,$ and acts at point $B=(0,420)mm.$ Determine the total moment about point O due to these two forces. Remember to follow the standard sign convention for clockwise $(-)$ and counter$-$clockwise $(+)$ moments.

$M_O=494911\mathrm{.}2$

$N-mm$