Avenues Of Approach
There are many different directions from which an opponent may enter your defensive sphere. But there are eight directions from which he may attack that would not only permit him to enter but to off-balance you as well. These eight directions are referred to as the eight Avenues Of Approach.

Angles Of Evasion
The angles of evasion correspond with the avenues of approach in that they are the same angles in relation to your position. Just as an attack may come from angles which could off-balance you, so you may use the eight avenues of approach in a reverse manner. Thus they become the angles of evasion.