Defining a Line Segment
A line segment is a part of a straight line that is bounded by two distinct end points. It contains these endpoints and every point on the line between them. Unlike a line, which extends infinitely in both directions, a line segment has a fixed, measurable length.
Section 2: Key Properties
The defining property of a line segment is its finite length. This length is the distance between its two endpoints. A line segment is one-dimensional and is typically named by its two endpoints, for example, line segment AB (often written as AB with a bar over it).
Section 3: A Practical Example
Consider the edge of a book, a side of a square, or a single rung on a ladder. These are all physical representations of line segments. In a drawing, if you mark two points, A and B, on a piece of paper and connect them with a straight ruler, you have drawn line segment AB.
Section 4: Why Line Segments are Important
Line segments are the fundamental building blocks of most geometric shapes. Polygons, such as triangles, rectangles, and pentagons, are defined as closed figures made up of a finite number of connected line segments. Understanding them is essential for calculating concepts like perimeter, area, and the properties of shapes.