Coulomb's Law

1. The problem



Two negative and two positive point charges (magnitude Q = 3.16mC ) are placed on opposite corners of a square (side lengths a = 0.105m )



#1. Determine the magnitude of the force on each charge.



I GOT..... F=7.44x10^6N (which was marked correct)



I am having trouble with this question.....



#2. Determine the direction of the force on each charge.

I know (Fy/Fx)=1

so tan-1(1)=45



Its asking for θ1,θ2,θ3,θ4 and I have no idea how to get the angles :(

Attached Images

74f4a70d1ac54e4986e402b658bea139_A.jpeg (41.8 KB)