Magnitude of point P center (I'm Stumped)

[Physrook 09]

Homework Statement

Four identical point charges, Q, are placed at the corners of a square. Each side of the square has length 2.0 m. Determine the magnitude of the electric field at the point P, the center of the square.

Homework Equations

(k)(q)/r2

The Attempt at a Solution

 

[gamer_x_]

What's the first step in any electrostatics problem?

 

[Physrook 09]

Find the electric field? Which is 0.