Line Segment: Definition, Measurement and Examples

Collegedunia Team logo

Collegedunia Team Content Curator

Content Curator

Line segments are defined as points along a line that are bounded by two distinct points. You can also think of a line segment as the portion of the line that connects two points. A line segment has two fixed or definite endpoints, but a line has no fixed endpoints and extends infinitely in both directions. A line segment is a part of a line that has two ends and is the shortest distance between them. 

Also read: Isosceles Triangle Theorems

Line Segment Definition

There are always two endpoints in a line segment. Each segment of the line is always the same length since it is the distance between two fixed points. In this situation, you can measure the length in metric units such as centimeters (cm) or millimeters (mm), or use conventional units like feet or inches. As you study lines and angles, you will come across their basic terminologies. However, you will learn about their advanced versions.

Read More:

Quadrilateral Formula

Trapezoid Formula

Tan2x Formula

An open line segment is made up of only one of the two endpoints, whereas a closed segment has both of them. Line segments that have exactly one endpoint are called half-open segments.

Also Read:


Line segment Symbol

Line segments with two endpoints A and B are denoted with the bar symbol (—), such as AB.

Lines are typically illustrated by the left-right arrow (↔) and rays by arrows to the right(→).

Read More:


Line Segment Measurement

What is the best method for measuring a segment of a line? In this section, we will explore several methods.

Read More:

Surface Area of a Cylinder Formula

Sphere Formula

Slope Formula

Observation-based

A simple observation is the most trivial way to compare two line segments. The length or shortness of two line segments can easily be determined by looking at them in comparison.

Read More:

Integers As Exponents?

Ordinate?

Collinear points?

As you can notice, by observation alone, line segment CD is longer than line segment AB in the above figure. However, this method is not without limitations since we cannot rely simply on observation whenever comparing two line segments.

Line Segment Measurement
Line Segment Measurement

Trace paper application

Trace paper makes it easy to compare line segments. By tracing one segment of a line and placing it over the other, it can be determined which is longer. Repeat the process as many times as necessary for multiple segments of a line.

Read More:

It is necessary to trace the line segments accurately to perform a precise comparison. As a result, this method relies on the accuracy of trace analysis, which limits its application.

Read More:


Line Segment Construction

The purpose of this lesson is to teach you how to draw a line segment with a compass and ruler. Consider a situation in which we need to draw a 5.6 cm long line segment. Here are the steps to follow:

  • The length of the line segment should be considered when drawing any line without a measurement.
  • Draw a line segment from point A to B, which will serve as the starting point.
  • Use a ruler or scale to locate the compass’s pointer which is 5.6 cm from the pencil's lead.
  • Place the pointer of your compass at point A on the line and mark an arc with your pencil using the same measurement.
  • You can now mark this point as B

Read More:

Thus, AB is the 5.6 cm-long line segment that must be drawn.

Line Segment Construction
Line Segment Construction

Line Segment Examples

Two-dimensional geometry has several examples of line segments as each polygon is made up of line segments. 

Read More:

  • The triangle is made up of three line segments connected end to end.
  • There are four line segments that make up a square.
  • Five-line segments make up a pentagon.

As a result, line segments play a crucial role in geometry

Read More:


Things to Remember

  • There are always two endpoints in a line segment.
  • It is the shortest distance between a line that has two endpoints.
  • Line segments that have exactly one endpoint are called half-open segments.
  • Line segments are denoted with the bar symbol (—).
  • The triangle is made up of three line segments connected end to end.
  • There are two ways to measure a line segment- Observation-based and Trace paper application.

Read More:


Sample Questions

Ques: Describe the concept of a line segment. What is the difference between a line segment and a line?

Answer: As the name suggests, a line segment is a portion of a line with two distinct endpoints. Those endpoints are definite.

In contrast to a line segment, which has endpoints, a line extends infinitely at both ends.

Read More:

Ques: Are there any differences between line segments and rays?

Answer: There is only one endpoint on a ray, while there are two on a line segment. In a ray, the endpoints are indeterminate, but in a line segment, the endpoints are always definite.

Read More:

Ques: How do you symbolize a line segment? What is an example of a line segment in real life?

Answer: A dotted line segment is denoted by a Bar (—) at the top of its notation, say AB.

There are many examples of line segments, including rulers, scales, sticks, boundary lines, etc.

Read More:

Ques: What are the Steps Involved in Constructing a Line Segment?

Answer: Assuming your task is to draw a line segment of 3 centimeters. Follow the below-mentioned steps to complete your task:

  • Draw a straight line of no specific measurement keeping in mind that it is longer than the line segment you have to draw.
  • Mark a dot C on the line which will be the starting point of your line segment.
  • Now widen the compass and using a measuring scale, ensure that the distance between the tip of the compass and the tip of the pencil is 3 centimeters apart.
  • Place the tip of the compass at point C on the line that you had drawn and draw an arc 3 centimeters from point C. 
  • Mark the point where the arc meets the line, as D.
  • Hence, CD is the required line segment of length 3 centimeters.

Also Read:

CBSE X Related Questions

  • 1.

    In the adjoining figure, TS is a tangent to a circle with centre O. The value of $2x^\circ$ is

      • 22.5
      • 45
      • 67.5
      • 90

    • 2.

      Given that $\sin \theta + \cos \theta = x$, prove that $\sin^4 \theta + \cos^4 \theta = \dfrac{2 - (x^2 - 1)^2}{2}$.


        • 3.

          Directions: In Question Numbers 19 and 20, a statement of Assertion (A) is followed by a statement of Reason (R).
          Choose the correct option from the following:
          (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
          (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
          (C) Assertion (A) is true, but Reason (R) is false.
          (D) Assertion (A) is false, but Reason (R) is true.

          Assertion (A): For any two prime numbers $p$ and $q$, their HCF is 1 and LCM is $p + q$.
          Reason (R): For any two natural numbers, HCF × LCM = product of numbers.

            • Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
            • Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
            • Assertion (A) is true, but Reason (R) is false.
            • Assertion (A) is false, but Reason (R) is true.

          • 4.
            If the zeroes of the polynomial $ax^2 + bx + \dfrac{2a}{b}$ are reciprocal of each other, then the value of $b$ is

              • $\dfrac{1}{2}$
              • 2
              • -2
              • $-\dfrac{1}{2}$

            • 5.
              In a right triangle ABC, right-angled at A, if $\sin B = \dfrac{1}{4}$, then the value of $\sec B$ is

                • 4
                • $\dfrac{\sqrt{15}}{4}$
                • $\sqrt{15}$
                • $\dfrac{4}{\sqrt{15}}$

              • 6.
                AB and CD are diameters of a circle with centre O and radius 7 cm. If \(\angle BOD = 30^\circ\), then find the area and perimeter of the shaded region.

                  Comments


                  No Comments To Show