Calculating Magnetic Field Strength and Direction in a Multi-Wire System

[griercorleone]

please help??

1. Homework Statement

I got 1/2 of this problem right, but I am not sure of the other part. I have attached the picture. The questions are as follows (with the answers that I am sure of) --

What is the magnetic field strength at point 1 in the figure?
What is the magnetic field direction at point 1 in the figure? (out of the page)
What is the magnetic field strength at point 2 in the figure?
What is the magnetic field direction at point 2 in the figure? (in to the page)
What is the magnetic field strength at point 3 in the figure?
What is the magnetic field direction at point 3 in the figure? (out of the page)

2. Homework Equations

B = permeability constant * I/ 2(pi)r


3. The Attempt at a Solution
Well, for the first one example, this is what I did.

(1.257*10e-6)*(10)/2(pi)(.02m) = 1*10e-4

This is not correct however? Can someone give me some instruction? And for the second and third ones, which wire am I calculating from?

 

[ideasrule]

You haven't attached a picture.