1. The problem statement, all variables and given/known data Consider an equilateral triangle of side 15.6 cm. A charge of +2.0 µC is placed at one vertex and charges of –4.0 µC each are placed at the other two, as shown in the diagram to the right. Determine the electric field at the centre of the triangle. I've found the distance from each point to the centre. Now do I just find the electric field of each compared to the centre and add all three together?