The figure below shows three very long straight wires $($in cross section$)$ that each carry a current of $4\mathrm{.}00$ A out of the page. Distance d$1=6\mathrm{.}00$ m and distance d$2=4\mathrm{.}00$ m $.$ What are $($a$)$ the magnitude and $($b$)$ the direction $($relative to the positive direction of the x axis$)$ of the net magnetic field at point P$,$ which lies on a perpendicular bisector to the wires?