A Great
Circle Track going from East to West in the Northern Hemisphere will always
decrease in value (and West to East will increase in value). The reverse is
true of the Southern Hemsiphere.
However, I don't recommend that you try to learn these facts but rather
to draw a diagram (free hand - no need for super accurate drawings!) and to
estimate the value of the track angles from the drawing, i.e. estimate whether
A is greater than B or vice versa.
Here the track angle at 035訖, being the meridian where the track reaches the
highest latitude, will be either 090訊 or 270訊. As the aircraft is travelling West it will obviously be 270訊. Look at the track angle at
B and it can clearly be seen that the track angle at B is > 180訊 but <
270訊.