# CBSE Class 8 Maths Revision Notes Chapter 15

## CBSE Class 8 Mathematics Revision Notes Chapter 15 – Introduction to Graphs

In this Class 8 Mathematics Chapter 15 notes, students will learn about graphs. In addition, in this class 8 chapter 15 Mathematics notes, students will get to know the significant details of the chapter that are important for their final examination. Along with Chapter 15 Mathematics Class 8 notes, these CBSE revision formulas notes will provide students with essential questions that can be asked in the examination to consolidate their preparation. Moreover, Class 8 Mathematics chapter 15 notes will be a student’s last-minute revision guide providing all the necessary information. This class 8 Mathematics notes chapter 15 is taken out of NCERT books of the CBSE syllabus to help students answer important questions. These notes are based on the CBSE syllabus.

When the data is presented in a graphical format, it is easier to understand:

• A bar graph is employed to show comparisons between categories
• A pie graph is employed to compare portions of a whole
• A bar graph where data is displayed in intervals is called a histogram
• A graph that depicts data that is constantly changing throughout time is called a line graph
• A graph that is made up of a single continuous line is called a linear graph
• The xx-coordinate and yy-coordinate is required to fix a point on the graph sheet.
• A graph depicts the relationship between the dependent and independent variables.

### Access Class VIII Mathematics Chapter 15 – Introduction to Graphs Notes

A Bar Graph

• It is a graphical representation of numerical data formed by uniformly sized bars, in the shape of rectangles, with equal spacing.
• The Length or height of each bar denotes the provided number.

A Pie Graph

• A pie graph is a visual depiction of how parts of a whole are in comparison to each other.
• The sectors of the circle represent the numerous observations or components.

Histogram

A histogram is a form of bar diagram where the class intervals are shown on the horizontal axis, and the heights of the bars (rectangles) represent the frequency of the class interval. No gap exists between the bars because a gap does not separate the class intervals.

Linear Graph

A line graph is a graph where all the line segments form one continuous line.

Coordinates

It is an ordered pair of numbers that represents a point on the Cartesian plane.

Ordered Pair

It is a set of numbers in a predetermined arrangement.

## Class 8 Mathematics Notes of Introduction to Graphs

### Revision Notes Class 8 Mathematics Chapter 15-Introduction to Graphs

Graphs are simply visual illustrations of the collected data. Graphical representation allows us to demonstrate the trend of the data. These graphs are applied in different fields, and it is of great help to people. Graphs can be of various types, and each of these serves a specific function.

#### Points to Remember for Introduction to Graphs

In these class 8 chapter 15 notes, these are the points that need to be remembered.

• The x-coordinate of a given point is the distance from the y-axis.
• The y-coordinate of a given point is the distance from the x-axis.
• The origin coordinates in a graph are valued at (0, 0).
• The x-coordinate of each point lying on the y-axis is 0
• The y-coordinate of each point lying on the x-axis is 0
• A linear graph is a line graph that’s completely an unbroken line.
• A bar graph helps to show and express the correlation between the categories.
• A pie graph helps to measure parts of a whole.
• A line graph helps to show data that frequently changes over periods of time.
• A histogram is a class of graphs that shows data at intervals.
• We require an x-coordinate and y-coordinate to fix a point on the graph.
• A graph helps in displaying the relationship between a dependent variable and an independent variable.

### Types of Graphs Represented in Class 8 Revision Notes Introduction to Graphs

• Bar Graph-It is a kind of graph that is created to show comparisons between different categories. In the Bar graph, bars of uniform width is used to show the different quantities, and their height is kept equal to the values they represent.
• Double Bar Graph- This is similar to the bar graph, but the two types of data are shown correspondingly. This form of a graph is useful for displaying a comparison between two data.
• Pie Chart- Pie chart is used to represent the given data in a circular form. It is also referred to as the Circle Graph. When the data is shown in a circular form, it is referred to as a pie chart. A pie chart shows the part of a whole.
• Line Graph- The line graph can be used when changes continuously can be seen over a given period of time.
• Linear Graphs- In a Linear Graph, all the line segments form one continuous line.
• Histogram-We can form a histogram when we have a date that is grouped together in class intervals. It is a type of bar graph. The main difference between a histogram and a bar graph is that there is no gap between the bars, as this is a graph of continuous data.

### Introduction to Coordinates in Chapter15 Class 8 Mathematics Revision Notes

The x-coordinate of a point shows the distance we have to cover from origin O to left or right along the x-axis. At the same time, the y-coordinate of a point displays the distance we have to cover below or above O along the y-axis.

These CBSE revision notes are made according to the CBSE syllabus. The questions in these notes are based on CBSE’s previous year’s question papers. These notes contain important questions and formulas to help students achieve better marks in their examinations.

### 1. What do you mean by the location of a point in Mathematics Class 8 introductions to graphs notes?

To make a linear graph, we have to use the Cartesian plane. A Cartesian plane is a graphical system where we can mark by considering the horizontal and vertical lines. It is like a square grid sheet that is divided into four quadrants by making a horizontal line (x-axis) and a vertical line (y-axis).

### 2. What is the purpose of making graphs?

The main purpose of making graphs is to show numerical facts in visual form for their quick and improved understanding. It is particularly very useful where there is a trend or comparison to be explained.

### 3. Name some applications of graphs.

In our daily life, we see two quantities that are interlinked, i.e., the change in one quantity goes along with the change in the other quantity.

### 4. Mention a daily life example of the application of a graph.

We can take the example of overtime. A bonus is given if an employee works overtime. The more rice we buy, the more we have to pay. In the first situation, the amount of bonus is called the dependent variable, and the number of hours is termed the independent variable. In the second situation, the amount paid to buy the rice is the dependent variable, whereas the amount of rice is the independent variable. So, the relation between the dependent and independent variables can be shown on a graph.