Neither one way nor the other
The last case: the two forces are inclined to one another — neither parallel nor along one line.
Figure to be added
Two forces P and Q acting inclined to one another on an object are shown in figure 9.11. When two inclined forces like these are applied to an object, the object moves neither in the direction of P nor in the direction of Q.
Two inclined forces
In such a case the direction in which the object moves is a direction lying between the directions in which the two forces act.
This is not hard to see
If P acted alone the object would go the way P points. If Q acted alone it would go the way Q points. With both applied at once, neither one "wins" — the object goes to a compromise between the two. It is not like a tug of war; it is more like two people pushing the same cart in two slightly different directions.
The chapter stops here
Only the direction of the resultant of two inclined forces is given here. Finding its magnitude — what the answer comes to when 5 N and 12 N are applied at an angle — does not belong to this chapter. That needs a method for adding vectors, which comes in later classes. So when you meet two inclined forces, do not try to add them or subtract them.
On inclined forces this chapter asks one thing only: recognising where the direction of motion lies.