# Find the equation of a straight line on which length of perpendicular from the origin is four units and the line makes an angle of $120^{\circ}$ with the positive direction of $x$ - axis. [Hint: Use normal form, here $\omega =30^{\circ}$.]
$\begin {array} {1 1} (A)\;\sqrt 3x+y=8 & \quad (B)\;x+y\sqrt 3 =8 \\ (C)\;\sqrt 3 x-y=8 & \quad (D)\;x-y\sqrt 3=8 \end {array}$