Wings generate lift according to the angle of attack. A symmetrical wing can generate lift. Also, consider that many planes can fly upside-down.
The specific cross-sectional shape allows them to produce lift at a lower angle of attack, without stalling. That's particularly useful if you want to take off.
There's also stuff like the Coanda effect, Bernoulli's principle, and lots of other complicated stuff, eventually ending in "nobody knows".
(, Sat 29 May 2021, 13:42, Share, Reply)