 Point and lines - Orchids The International School Geometry

Point and lines

Geometry is a branch of mathematics, that is primarily concerned with the shapes and sizes of objects, their relative position, and the properties of space. Here we will discuss the point, line, line segments and rays.

Point

In geometry, a point is a location represented by a dot. A point does not have any length, width, shape or size, it only has a position. Generally, the points are named with capital letters. A line is made of a set of points. A line has no thickness and can extend indefinitely in both directions. The length of a line is undefined and it can have an infinite number of points. In the below picture, AB is a line. There are two types of lines –

(i) Straight lines (ii) Curved lines Straight line:A straight line is a line that does not have any curve in it. There are different types of straight lines. Curved lines:When a line is not straight, it is called a curved line.

Line Segment

A line segment is a part of a line that has two endpoints and a fixed length. Line and line segments are different. A line segment cannot be extended indefinitely in both directions. In the below picture, MN is a line segment. Ray is a part of a line that has a start point but no definite endpoint. A ray can be extended to infinity in one direction. In the below picture PQ is a ray. Did you Know:

The lights originate from the sun. In space, the path of these lights travels indefinitely in straight lines and in one direction. Since the light has one starting point (The sun) and can extend indefinitely in one direction, these lights are called Sunrays. Misconceptions:

Students often confuse between the line, line segment and ray. In spite of the similarities, there are many differences among these. Here it is explained in brief.

Line Line segment Ray
A line can be extended in both directions indefinitely. A line segment is a part of a line. It cannot be extended indefinitely in both directions. A ray is a part of a line that has an endpoint and can be extended indefinitely in one direction.
It has no endpoint It has two endpoints It has one endpoint • -