Before we could discuss this in any specific detail, I think we would have to know the angles. A generic discussion without actual numbers for the angles would be just plain too confusing.
The general approach is that the vertical components of both tensions add up to 20N, and the horizontal components are equal but in opposite directions. That's the only way that the mass is hanging motionless.
You have to find the horizontal and vertical components of the tensions by using the angles and maybe the lengths of the ropes.
