Three charges, $A(+6\mathrm{.}0C),B(-5\mathrm{.}0C),$ and $C(+6\mathrm{.}0C),$ are located at the corners of a rectangle $(A,B,C,$ located clockwise$)$ with sides that are $5\mathrm{.}0$ cm long and $10$ cm wide. What is the electric field at point D$?$ D is at the fourth corner of the rectangle.