if 3 forces are in equilibrium, what is the relation between any of d 3 forces & d resultant of other 2 force?

Question

this is my 2nd question:

if two forces with the same magnitude were exactly in the opposite directions, what is the magnitude and direction of their resultant? what is the magnitude and direction of their equilibrant?

Answer 1

Any one of three forces is equal and opposite ( or is the equilibrant) of the resultant of the other two forces.

2nd question.

Magnitude is zero and direction is null.

The magnitude of the equilibrant is zero and direction is null.

Answer 2

Necessary and sifficient conditions for three forces to be in static equilibrium are:
sigmaX,SigmaYand SigmaM have to be zero.
The algebraic summation of all components of forces resolved along Xaxis, Y axis and Moments about any reference points have to be zero.
The resultant of rhese forces have to be zero.
The resultant of two forces equal in magnitude and opposite in direction has to be zero, provided they are acting along the same axis. If not it will result in a couple causing rotation. If the magnitude of resultant is zero there no question of equilibrant.

Answer 3

Equal in magnitude and opposite in direction.