A polygon is defined as a figure bounded by:

A polygon is indeed defined as a figure that is bounded by any number of straight lines. These lines, called sides, connect to form a closed shape. The simplest polygon is a triangle, which has three sides, but polygons can have more than three sides, including quadrilaterals with four sides, pentagons with five sides, hexagons with six sides, and so on, extending to many-sided shapes.

This definition encapsulates a wide variety of shapes rather than limiting polygons to a specific number of sides or types of shapes. Therefore, the option that states a polygon is formed by any number of straight lines accurately captures this inclusive definition, recognizing both simple and complex polygons without restriction.