To make it more aerodynamic.
The majority of commercial planes have curved wings. The only purpose of removing them is for airborne stunts, and as such passenger and cargo planes have no reason not to have curved wings. Military and stunt planes will have wings that are closer to or perfectly flat, depending on the maneuverability needed.
For better airflow.
Approximately 36 aircraft in a wing
Cessnas have high wing, and most other small planes have low wing.
That can be a squadron, or maybe a 'wing'...
Because they are curved or they are slanted
as big as a planes wing
Rudder on the wing of the plane controls the direction.
The top surface of an airplane wing is curved to create lift. Because of the curve, air has to travel farther across the top of the wing than across the bottom; this creates a low-pressure condition that pulls the airplane into it.
A plane's wingspan is the length of it's wing.
the wing flaps go up and down
Planes like B-2 Bomber And F-117 Nighthawk are these king of planes. They fly one main wing. They are called Omniwings.