Three positive point charges are arranged in

Question

a triangular pattern in a plane as shown.
+
2 nC
+
4 nC
+
6 nC
Distance between all: 7 m
I don't know how to d this part:
Find the magnitude of the net electric force
on the 4 nC charge. The Coulomb constant is
8.98755 × 109 N · m2
/C
2
.
Answer in units of N.
017 (part 2 of 2) 10.0 points
What is the direction of this force (measured
from the positive x-axis as an angle between
−180◦and 180◦
, with counterclockwise positive)?
Answer in units of ◦