Your answer is partially correct. Review Conceptual Example 11 before attempting to work this problem. Four charges with equal magnitudes of 10.2 x 10-12 Care placed at the corners of a rectangle. The lengths of the sides of the rectangles are 3.57 cm and 6.64 cm. Find the magnitude of the electric field at the center of the rectangle in Figures a and b. +4 (a) (a) Number 130 Units N/C (b) Number 260 Units N/C