The figure shows three displacement vectors vec$(A),$vec$(B),$ and vec$(C).$ These vectors are arranged in tail$-$to$-$head fashion, and they add together to give a resultant displacement vec$(R),$ which lies along the x axis. Note that vector vec$(B)$ is parallel to the $x$ axis. What is $($a$)$ the magnitude of vector vec$(A)$ and $($b$)$ its directional angle $?$

$($a$)$ Number

$($b$)$ Number

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