Consider an equilateral triangle of side 15.6cm. A charge of +2.0μC is placed at one vertex and charges -4μC each are placed at the two. Determine the electric field at the centre of the triangle. I used Pythagoreom theory to find the height and divided it by 2 but now I'm stuck because I realized it's not exactly the middle of the triangle, but rather the middle of the triangle side =/ How do I go from there to find the centre? Then I basically will use the formula E = kQ / r2, for the charge +2.0μC towards the centre. And correct me if I'm wrong, but do the electric field at the bottom end up cancelling out, or just the x-components of their electric field?