Maths Formulas for Class 9

Maths Formulas for Class 9

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

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

Class 9 Math Formulas Tables

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

Geometry

Geometry Shapes Formulas for Class 9
Geometric Figure	Area	Perimeter
Rectangle	A= l × w	P = 2 × (l+w )
Triangle	A = (1⁄2) × b × h	P = a + b + c
Trapezoid	A = (1⁄2) × h × (b1+ b2)	P = a + b + c + d
Parallelogram	A = b × h	P = 2 (b + h)
Circle	A = π r2	C = 2 π r

Algebra

Algebraic Identities For Class 9

(a+b)2=a2+2ab+b2

(a−b)2=a2−2ab+b2

(a+b)(a–b)=a2–b2

(x+a)(x+b)=x2+(a+b)x+ab

(x+a)(x–b)=x2+(a–b)x–ab

(x–a)(x+b)=x2+(b–a)x–ab

(x–a)(x–b)=x2–(a+b)x+ab

(a+b)3=a3+b3+3ab(a+b)

(a–b)3=a3–b3–3ab(a–b)

(x+y+z)2=x2+y2+z2+2xy+2yz+2xz

(x+y–z)2=x2+y2+z2+2xy–2yz–2xz

(x–y+z)2=x2+y2+z2–2xy–2yz+2xz

(x–y–z)2=x2+y2+z2–2xy+2yz–2xz

x3+y3+z3–3xyz=(x+y+z)(x2+y2+z2–xy–yz−xz)

x2+y2=12[(x+y)2+(x–y)2]

(x+a)(x+b)(x+c)=x3+(a+b+c)x2+(ab+bc+ca)x+abc

x3+y3=(x+y)(x2–xy+y2)

x3–y3=(x–y)(x2+xy+y2)

x2+y2+z2−xy–yz–zx=12[(x−y)2+(y−z)2+(z−x)2]<

Surface Area and Volumes

Shape	Surface Area	Volume
Cuboid	2(lb + bh +lh) l= length, b=breadth, h=height	lbh
Cube	6a2	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

\(Area ~of~ triangle~ using~ three~ sides =\sqrt{s(s-a)(s-b)(s-c)} \\)

Semi-perimeter, s = (a+b+c)/2

Polynomial

Polynomial Formula

P(x)=anxn+an−1xn−1−an−2xn−2+……+ax+a0

Statistics

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

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