 # CBSE Class 9 Maths Revised Syllabus for 2020-21

## CBSE Class 9 Maths Revised Syllabus for 2020-21

Maths is an interesting subject that focuses on the study of numbers, shapes and patterns. Besides, maths help to solve problems that can be related to the real world and as everything in this universe follows a pattern the subject of mathematics can be applied in many instances. The importance of the subject can also be seen like every other subject incorporates the basic knowledge of mathematics in one way or the other. CBSE Class 9 Maths Revised Syllabus for 2021-22.

Contents

## Students can access CBSE Class 9 Maths notes from the table mentioned below:

Chapter 1 – Number System

We use numbers in our day to day life. They are often called numerals. Without numbers, we cannot do counting of things, date, time, money, etc. Sometimes these numbers are used for measurement and sometimes they are used for labelling. The properties of numbers make them capable of performing arithmetic operations on them.  These numbers are expressed in numeric forms and also in words. For example, 2 is written as two in words, 25 is written as twenty-five in words, etc. Students can practice writing the numbers from 1 to 100 in words to learn more.

There are different types of numbers in Maths, which we learn. They are natural and whole numbers, odd and even numbers, rational and irrational numbers, etc. We will discuss all the types here in this article. Apart from these, the numbers are used in various applications such as forming number series, maths tables, etc.

Chapter 2 – Polynomial

Polynomial derived from the words “poly” which means “many” and the word “nomial” which means “term”. In maths, a polynomial expression consists of variables which are also known as indeterminates and coefficients. The coefficients involve the operations of subtraction, addition, non-negative integer exponents of variables and multiplication.

Chapter 3 – Coordinate Geometry

Coordinate system is used to locate the position of a point in a plane using two perpendicular lines. Points are represented in the form of coordinates (x, y) in two-dimension with respect to x- and y- axes. In this article, we will learn what is Cartesian Coordinate system.

To understand the need of coordinate geometry, let us consider an example, suppose Rina is a girl in your class and she sits on the 3rd column and 5th row. Then this position can be represented as (3, 5).

Chapter 4 – Linear Equations in Two Variables

When an equation has only one variable of degree one, then that equation is known as a linear equation in one variable.

When an equation has two variables both of degree one, then that equation is known as a linear equation in two variables.

Chapter 5 – Introduction to Euclid’s Geometry

The word “geometry” comes from the Greek words “geo”, which means the “earth”, and “metron”, which means “to measure”. Euclidean geometry is a mathematical system attributed to Euclid, a teacher of mathematics in Alexandria in Egypt. Euclid gave us an exceptional idea regarding the basic concepts of geometry, in his book called “Elements”.

Chapter 6 – Lines and Angles

The chapter Lines and Angles, covers various concepts such as parallel lines, transversal angles, intersecting lines, interior angles are explained with the examples.

Chapter 7 – Triangles

In the chapter Triangles, the concept of triangles covers the following concepts such as congruency, criteria for the congruence such as SAS, SSS, ASA, AAS, RHS are explained here in detail. Two triangles are said to be congruent if all their three sides and three angles are equal. But it is necessary to find all six dimensions. Hence, the congruence of triangles can be evaluated by knowing only three values out of six. The meaning of congruent in Maths is when two figures are similar to each other based on their shape and size.

A quadrilateral is a shape which has four sides. In this chapter, we are going to discuss the different types of quadrilaterals such as square, rectangle, parallelogram properties with proofs.

Chapter 9 – Areas of Parallelograms

In Geometry, a parallelogram is a two-dimensional figure with four sides. It is a special case of the quadrilateral. The sum of the interior angles in a quadrilateral is 360 degrees. A parallelogram has two pairs of parallel sides with equal measures. Since it is a two-dimensional figure, it has an area and perimeter.

Chapter 10 – Circles

• The set of all the points in a plane that is at a fixed distance from a fixed point makes a circle.
• A Fixed point from which the set of points are at fixed distance is called the centre of the circle.
• A circle divides the plane into 3 parts: interior (inside the circle), the circle itself and exterior (outside the circle)

Chapter 11 – Constructions

• If a ray stands on a line then the adjacent angles form a linear pair of angles.
• If two angles form a linear pair, then uncommon arms of both the angles form a straight line.

Chapter 12 – Heron’s Formula

In Geometry, a triangle is a closed three-dimensional figure. In this chapter, you are going to learn the Heron’s formula for class 9, which is used to find the area of triangles. Also, how Heron’s formula is used to find the area of other polygons in detail.

Chapter 13 – Surface Areas and Volumes

In this chapter, the complete surface area and volume formulas for different three-dimensional shapes are discussed with the complete explanation. For any three-dimensional figures, the surface area can be broadly classified into Curved Surface Area(CSA), Lateral Surface Area (LSA), and Total Surface Area (TSA). These can be computed for 3d shapes such as a cube, cuboid, cone, cylinder and so on.

Chapter 14 – Statistics

A study dealing with the collection, presentation and interpretation and analysis of data is called statistics.

Chapter 15 – Probability

Probability means possibility. It is a branch of mathematics that deals with the occurrence of a random event. The value is expressed from zero to one. Probability has been introduced in Maths to predict how likely events are to happen.

The meaning of probability is basically the extent to which something is likely to happen. This is the basic probability theory, which is also used in the probability distribution, where you will learn the possibility of outcomes for a random experiment. To find the probability of a single event to occur, first, we should know the total number of possible outcomes.

## CBSE Class 9 Deleted Portion of Syllabus for 2021-2022

Check subject-wise details of the deducted portion of CBSE Class 9 syllabus from the following links:

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