1. The problem statement, all variables and given/known data What is the electric field strength at the center of the triangle? Three 13.0 -cm-long rods form an equilateral triangle. Two of the rods are charged to + 19.0 nC, the third to - 19.0 nC . What is the electric field strength at the center of the triangle? 2. Relevant equations E=(kq)/r^2 lambda=deltaQ/deltax 3. The attempt at a solution I've attempted this problem about 4 times and got all different but wrong answers. In each attempt I figured that the electric fields created by the two positively charged rods cancel each other out everywhere (This is where I believe I have made my mistake) and that the electric field depends only on the negative charged rod. I also figured by symmetry that the components of the electric field to the left and right (x-axis I chose) cancel each other out and the only electric field felt at the center is downwards (Y-axis I chose). Is my mistake based on that I figured the two positively charged rods cancel each others electric fields out? I'm looking for some tips and hints to get me on track for this problem. Thank you.