Two point charges, q1 = -12.5 ?C and and q2 = +18.7 ?C, are placed at two of the corners of a right triangle with a = 23.5 cm and b = 13.0 cm, as shown in the figure.
a) Find the magnitude of the electric field at the third corner of the triangle.
b) Determine the direction of electric field at the third corner of the triangle (angle with respect to the positive x-axis).