What is the term used to describe the shape of a wing when viewed from above?

The term that describes the shape of a wing when viewed from above is "wing planform." This term is used in aerodynamics to refer specifically to the outline of the wing as seen from a top-down perspective. The planform shape is crucial because it affects the aerodynamic qualities of the wing, including lift generation, drag characteristics, and overall performance attributes.

The planform can vary significantly in shape, including options such as rectangular, trapezoidal, and elliptical. Each of these shapes influences how air flows over the wing, which in turn affects the aircraft's stability and maneuverability.

In contrast, other terms listed refer to different aspects of wing design and performance. Wing aspect ratio refers to the ratio of the wingspan to the average wing width and is important for understanding lift and drag characteristics. Wing area is the total surface area of the wing, which is also a key factor in determining lift. Wing shape, while a general term, does not specifically denote the top-down view and could refer to various characteristics of the wing. Therefore, "wing planform" is the precise term that captures the intended definition in the context of the question.