Here you go, Piston area and force.

Sometimes, in fact most of the time, a word will be used that is accepted and understood which is not technically accurate.
For example, 12 Volt is accepted as an approximation for system voltage even though in reality the system runs between 14 and 14.8 Volts 99+% of the time. Likewise the connections to the power supply is often marked B, Bat, or Batt for 'battery', even though the system power doesn't usually come from the battery.
If you are someone like Paul Harrell with the skill, patience, and situation to explain something like that as part of the discourse, wonderful. That heads off the "Actually" comments.
So while your observation is more or less technically correct, all your post really does is reinforce Harrison's main point.