Electric Fields in Equilateral Triangle

[longcatislong]

Homework Statement

A point charge q = +2.0 µC is placed at each corner of an equilateral triangle with sides 0.23 m in length.
What is the magnitude of the electric field at the midpoint of any of the three sides of the triangle?


3. I want to know if I did this correctly, or totally screwed it up

At point p, the midpoint between on a side, the electric fields will cancel from the two point charges directly opposite each other. The only electric field will be felt from the point charge that's on the tip of the triangle.

So, I did E=KQ/R^2. I found R=.23Sqrt2, by knowing I have a 30-60-90 triangle if a bisect it.

E=(9e9)(2e-6)/(.23Sqrt3)^2=113422 N/C

 

[Spinnor]

I don't get the same value for R, but it might just be me.