We'll simplify the quotient and establish this general rule of thumb:
At 60nm from a TACAN station, radials are 1nm apart. This relationship exists from the
TACAN station itself for as far as that TACAN is within range of reception, and the
relationship is linear.
Therefore, at 20nm, the radials are 20/60 or 1/3nm apart; at 45nm they are 45/60 or 3/4nm
apart and at 90nm they are 90/60 or 1 1/2nm apart, etc.
The understanding of this relationship is important for it is the analysis of your present
position defined in terms of radial/ DME as contrasted with your desired position (radial/DME)
that will determine how far off course you are.
As an NFO you will have to do more than fix your position with relation to a TACAN
station. Once you've established your TACAN position you must relate that position to a point
on the Earth.
NAVAIDS POSITIONING 2-7