A kite is a quadrilateral shape that has two pairs of adjacent sides with the same length and one pair of opposite angles that are congruent. The diagonals of a kite intersect at right angles. The longer diagonal is the only line of symmetry and exactly bisects the shorter diagonal.
The traditional recreational kite shape is the same as a geometric kite. Recreational kite builders attach a kite-shaped piece of cloth, paper or plastic to a t-shaped frame, then tie strings to the frame to hold and control the kite. The kite's shape gives it certain aerodynamic properties that enable it to fly. A kite operates under the same principles of flight as an airplane: lift, drag and thrust.
As air travels over the top of the kite, it creates a low pressure zone above the kite and lifts it off of the ground. The front of the kite has an obtuse angle, while the back of the kite narrows to an acute angle. Drag is the aerodynamic property that turns the kite to face into the wind. Air is caught beneath the kite when the string is taut, adding stability and lowering the angle of attack. The lower angle of attack maximizes airflow over the kite's surface in the same way that engine thrust increases airspeed.