Two vectors, vec$(r)$ and vec$(s)$ lie in the xy plane. Their magnitudes are $3\mathrm{.}56$ and $4\mathrm{.}71$ units, respectively, and their directions are $288$ and $81\mathrm{.}0,$ respectively, as measured counterclockwise from the positive $x$ axis. What are the values of $($a$)$ vec$(r)*vec(s)$ and $($b$)|vec(r)$vec$(s)|?$

$($a$)$ Number

Unit:

$($b$)$ Number

Units