Which symbol is utilized to represent fixed-wing aviation?

The correct symbol used to represent fixed-wing aviation is the triangle. This shape is commonly associated with aircraft because its triangular design can resemble the wings of an airplane when viewed from the side. Triangles convey stability and direction, which aligns with the characteristics of fixed-wing flight, where lift is generated primarily by the wings.

The other symbols, while they may have significance in various fields, do not have a strong connection to fixed-wing aviation specifically. The plus sign is typically associated with positive values or addition, the infinity sign represents something limitless or eternal, and the star often symbolizes excellence or achievement but does not inherently represent flight or aircraft. Therefore, the triangle stands out as an appropriate representation of fixed-wing aviation, capturing its essential form and function effectively.