Maths Formulas For Class 9 | List of Important Formulas for Grade 9

Maths formulas for Class 9 are provided here for the students who consider Mathematics subject as a nightmare and difficult to understand. This may cause them to feel reluctant and lose interest in their studies. Therefore, to help them understand Maths in a simple way, we have accumulated all the important formulas for the 9th standard Maths subject, which students can easily remember.

The formulas are given here as per the NCERT syllabus for all the topics such as Algebra, Geometry, Polynomials, etc.

Download the PDF for all Maths Formulas for Class 9

Also, read the chapterwise notes and study materials for Class 9 Maths to prepare for your examinations.

Class 9 Math Formulas Tables

When you are clear with the logic behind every formula, solving any kind of problem becomes easier. If you are perfect with all the below-mentioned formulas in Maths for Class 9 are listed chapter-wise, nothing can stop you from scoring maximum marks in the final examination.

Geometry

Geometry Shapes Formulas for Class 9
Geometric Figure	Area	Perimeter
Rectangle	A= l × w Here, l= length and w= breadth	P = 2 × (l+w )
Triangle	A = (1⁄2) × b × h Here, b= base and h= height	P = a + b + c Here, a,b,c are the sides of the triangle
Trapezoid	A = (1⁄2) × h × (b₁+ b₂) Here, b₁, b₂ are length of parallel sides of trapezoid.	P = a + b + c + d a,b,c,d are the sides of the trapezoid
Parallelogram	A = b × h Here, b= base and h= height	P = 2 (a+b) a and b are the sides of the parallelogram
Circle	A = π r² Here, r= radius of cicle	C = 2 π r

Algebra

Algebraic Identities For Class 9

\(\begin{array}{l}(a+b)^{2}=a^2+2ab+b^{2}\end{array} \)

\(\begin{array}{l}(a-b)^{2}=a^{2}-2ab+b^{2}\end{array} \)

\(\begin{array}{l}\left (a + b \right ) \left (a – b \right ) = a^{2} – b^{2}\end{array} \)

\(\begin{array}{l}\left (x + a \right )\left (x + b \right ) = x^{2} + \left (a + b \right )x + ab\end{array} \)

\(\begin{array}{l}\left (x + a \right )\left (x – b \right ) = x^{2} + \left (a – b \right )x – ab\end{array} \)

\(\begin{array}{l}\left (x – a \right )\left (x + b \right ) = x^{2} + \left (b – a \right )x – ab\end{array} \)

\(\begin{array}{l}\left (x – a \right )\left (x – b \right ) = x^{2} – \left (a + b \right )x + ab\end{array} \)

\(\begin{array}{l}\left (a + b \right )^{3} = a^{3} + b^{3} + 3ab\left (a + b \right )\end{array} \)

\(\begin{array}{l}\left (a – b \right )^{3} = a^{3} – b^{3} – 3ab\left (a – b \right )\end{array} \)

\(\begin{array}{l} (x + y + z)^{2} = x^{2} + y^{2} + z^{2} + 2xy + 2yz + 2xz\end{array} \)

\(\begin{array}{l} (x + y – z)^{2} = x^{2} + y^{2} + z^{2} + 2xy – 2yz – 2xz\end{array} \)

\(\begin{array}{l} (x – y + z)^{2} = x^{2} + y^{2} + z^{2} – 2xy – 2yz + 2xz\end{array} \)

\(\begin{array}{l} (x – y – z)^{2} = x^{2} + y^{2} + z^{2} – 2xy + 2yz – 2xz\end{array} \)

\(\begin{array}{l} x^{3} + y^{3} + z^{3} – 3xyz = (x + y + z)(x^{2} + y^{2} + z^{2} – xy – yz -xz)\end{array} \)

\(\begin{array}{l} x^{2} + y^{2} = \frac{1}{2} \left [(x + y)^{2} + (x – y)^{2} \right ]\end{array} \)

\(\begin{array}{l} (x + a) (x + b) (x + c) = x^{3} + (a + b +c)x^{2} + (ab + bc + ca)x + abc\end{array} \)

\(\begin{array}{l} x^{3} + y^{3} = (x + y) (x^{2} – xy + y^{2})\end{array} \)

\(\begin{array}{l} x^{3} – y^{3} = (x – y) (x^{2} + xy + y^{2})\end{array} \)

\(\begin{array}{l} x^{2} + y^{2} + z^{2} -xy – yz – zx = \frac{1}{2} [(x-y)^{2} + (y-z)^{2} + (z-x)^{2}]\end{array} \)

Surface Area and Volume Formulas for Class 9

Following maths formulas for class 9 are essential to solve mensuration questions.

Shape	Surface Area	Volume
Cuboid	2(lb + bh +lh) l= length, b=breadth, h=height	lbh
Cube	6a² a = side of the cube	a³
Cylinder	2πr(h+r) r = radius of circular bases h = height of cylinder	πr²h
Cone	πr(l+r) r=radius of base l=slant height Also, l²=h²+r², where h is the height of cone	(1/3)πr²h
Sphere	4πr²	(4/3)πr³

Heron’s Formula

Heron’s formula for class 9 to find the area of triangles is given as

\(\begin{array}{l}Area ~of~ triangle~ using~ three~ sides =\sqrt{s(s-a)(s-b)(s-c)}\end{array} \)
Semi-perimeter, s = (a+b+c)/2

Polynomial

Polynomial Formula for Class 9

\(\begin{array}{l}P(x)=a_{n} x^{n}+a_{n-1} x^{n-1}+a_{n-2} x^{n-2}+\ldots \ldots+a x+a_{0}\end{array} \)

Statistics

Important formulas for Class 9 statistics are listed below:

Measure of Central Tendency
Mean	Sum of Observation/Total number of observation = ∑ x/n
Median	[(n+1)/2]th term [For odd number of observation] Mean of (n/2)th term and (n/2+1)th term [For even number of observation]
Mode	Value which is repeated maximum time in a data set

Probability Formula for Class 9

Empirical Probability = Number of trials with expected outcome/Total number of Trials

Class Related Formulas

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MATHS Related Links
Learn Mathematics	Vector Algebra For Class 12
CBSE Class 9 Maths Examination 2018: Important 3 Marks Questions	Area Of Sphere
Algebra Patterns	Arithmetic Progression Examples
Hexagon Area Calculator	Quadratic
Differentiation Formula Table	Linear Equations In One Variable Class 8 Worksheet

MATHS Related Links

Learn Mathematics

Vector Algebra For Class 12

CBSE Class 9 Maths Examination 2018: Important 3 Marks Questions

Area Of Sphere

Algebra Patterns

Arithmetic Progression Examples

Hexagon Area Calculator

Quadratic

Differentiation Formula Table

Linear Equations In One Variable Class 8 Worksheet