How do you find the limits of areas on a chart?

Mxsmanic wrote:
Robert M. Gary writes:

The sectional chart is used with a plotter. The plotter measures
distance and can figure direction.

I googled for this and found only software.

I presume you mean the mechanical arm-like device that I've seen being
using with flat charts on tables in movies? Certainly that might be
useful, but what about during flight? Chart tables would be awkward
in the cockpit (although large aircraft with navigators might have
them).

Two answers. First, when I'm flying my Mooney around at near the speed
of sound I just have a rough idea of where the airspace is and use ATC
and the GPS to avoid it.
However, when I fly the J-3 (and when I first started flying) I carried
a small plotter. You can use it in flight. In fact I'm required to make
sure my students can use it in flight for navigation and diversion. You
can use it in flight.
I still carry a small plotter in the pocket of my seat. I have multiple
scales on it so I can use it for IFR charts too but it also works for
sectionals.

I have one that has a Wizwheel built in and I use it regularly. Its
easier for me to figure TAS using the wizwheel then puching numbers
into the GPS to computer it. The Wizwheel is still a close friend of
mine. When I flew the GPS, the Wizwheel, my watch, and my plotter were
the *only* navigation tools I had.

-Robert, CFII