in theory ...

The "model" sits in the centre of a closed square box.
One side of the box, in this case the front, is taken as the Drawing Sheet.
All the other sides then "hinge out" from this side to form a flat plane of drawing views.
  
In the case of 3rd Angle Projection (traditionally the American method) the view is projected from the model
onto the "box side" behind the viewer (facing the model) as shown with face 'A' below, further views are

generated in exactly the same manner for the other faces of the model.

This means that the view is on the same side of the model to the face it represents.

From the Drawing Sheet ...

The top side hinges up.

The bottom side hinges down

.
The back and left hand sides hinge
together to the left.

The right hand side hinges to the right.

in practice ...

A typical three view representation of the above model using 3rd angle projection.