What is the term for a closed plane figure made up of line segments?

The term for a closed plane figure made up of line segments is a polygon. Polygons are defined by having at least three sides and can take many forms, such as triangles, quadrilaterals, pentagons, and so on. The defining characteristic of a polygon is that it is a two-dimensional shape with straight sides that connect to form a closed figure.

Polygons can vary widely in the number of sides they have and the lengths of those sides, but the critical aspect is that all sides must be straight line segments that enclose a space. This differentiates them from other geometric figures that may be composed of curves or open lines.

Understanding the attributes of polygons is fundamental in surveying and geometry, as they appear regularly in various spatial configurations and help in calculating areas and perimeters in practical applications.