Kites can be square. Kites can be diamond-shaped. They can be made of paper, plastic, or cloth. You can buy fancy kites that are shaped like boxes or other three-dimensional objects. No matter what your kite looks like, all kites fly the same way.
Kites work like the wings on an airplane. Wind is the force that pushes the kite up into the sky. Most kites fly at an angle so that the wind blowing against the kite is pushed downward. Air flowing over the kite causes lifting force, just like on an airplane wing. A person on the ground holds the string, making the kite hover in the air. This pulling force almost balances the wind force. The lifting force from air passing over the kite overcomes the kite's weight and the force of gravity pulling it down. When the lift force equals the kite's weight, the kite hovers.