Displacement vector vec$($A$)$ points due east and has a magnitude of $3\mathrm{.}89$ km $.$ Displacement vector vec$($B$)$ points due north and has a magnitude

of $8\mathrm{.}93$ km $.$ Displacement vector vec$($C$)$ points due west and has a magnitude of $8\mathrm{.}77$ km $.$ Displacement vector vec$($D$)$ points due south and has

a magnitude of $2\mathrm{.}14$ km $.$ Find $($a$)$ the magnitude of the resultant vector vec$($A$)+$vec$($B$)+$vec$($C$)+$vec$($D$),$ and $($b$)$ its direction as a positive angle relative

to due west.

$($a$)$ Number

Units

$($b$)$ Number

Units