Three point$-$like charges are placed as shown in the figure, $a=18\mathrm{.}0cm$ and $b=50\mathrm{.}0cm.$ The charge $(q_3)$ is placed

half way on the $($b$)$ side. Find the magnitude of the electric field at the top left corner. Let $q_1=+2\mathrm{.}80C,q_2=+3\mathrm{.}80C,$

and $q_3=-4\mathrm{.}70C.$

$1589609\mathrm{.}58\frac{N}{C}$