Which wing design is characterized by a sharp leading edge and tapering to the rear?

The wing design characterized by a sharp leading edge that tapers to the rear is the swept wing. This design allows for improved aerodynamic efficiency at high speeds, as the tapering shape reduces drag associated with airflow over the wing. The angled position of the wing also helps delay airflow separation, which can enhance stability and control during flight, particularly in supersonic conditions. Swept wings are commonly used in many modern aircraft, especially those designed for high-speed travel, as they allow for better performance at greater altitudes and higher Mach numbers.

In contrast, delta wings have a triangular shape and do not typically feature the sharp leading edge described. Straight wings are rectangular or even blunt at the leading edge, and while circular wings are an entirely different concept often seen in experimental designs, they do not fit the description provided.