Question $1$: Similar Setup, Different Charge

Consider three charges placed at the corners of an equilateral triangle of side length $\text{'}$a$\text{'}.$ Two charges are $+$q and the third charge is $-$q$.$

a$)$ Sketch the electric field lines in the plane of the charges. b$)$ Find the location of a point where the electric field is zero. c$)$ Calculate the magnitude and direction of the net electric field at the center of the triangle.