Mxsmanic wrote in
:

I see tons of restricted areas, MOAs, Class B, C, D, E airspace, and
the like on charts, but no clear indication of how to locate the
boundaries of these areas other than by pure guesstimate based on
looking at the chart. On rare occasions I see a radial noted as the
boundary of an area, or a radius, but in many cases there is nothing.
How in the world are you supposed to know when you are inside or
outside one of these areas, if you are not flying miles away from
them?

Yes, GPS units and some other devices may provide real-time display of
one's position with these areas superimposed, but such devices have
not always been available.

The sectional depicts the borders very clearly, and it depicts the terrain
surrounding those borders as well as any nearby navigation aids.

To learn how to read a sectional, I would recommend Whitt's Flying site. It
has very useful and detailed lessons for a student who wants to learn how to
fly. And best of all, it's free.

http://www.whittsflying.com/