9th Standard Syllabus & Materials
9th Standard
TN 9th Tamil உள்ளத்தின் சீர் -கற்கண்டு (இலக்கணம்) - தொடர் இலக்கணம், ஆகுபெயர் Important Questions And Answers Study Material - QB365 Set A
NEW9th Standard
TN 9th Tamil உள்ளத்தின் சீர் -விரிவானம் (துணைப்பாடம்) - தாய்மைக்கு வறட்சி இல்லை! Important Questions And Answers Study Material - QB365 Set A
NEW9th Standard
TN 9th Tamil உள்ளத்தின் சீர் -கவிதை பேழை (செய்யுள்) - மார்கழி பெருவிழா Important Questions And Answers Study Material - QB365 Set A
NEW9th Standard
TN 9th Tamil உயிருக்கு வேர்-இலக்கணம் - பகுபத உறுப்பிலக்கணம் Important Questions And Answers Study Material - QB365 Set A
NEW9th Standard
TN 9th Tamil அமுதென்று பேர் - இலக்கணம்-எழுத்து -அளபெடை Important Questions And Answers Study Material - QB365 Set A
NEW9th Standard
TN 9th Tamil அமுதென்று பேர்-துணைப்பாடம் - ஆறாம்திணை Important Questions And Answers Study Material - QB365 Set A

Published on: 12/06/2021
QB365 provides detailed and simple solution for every book back questions in class 9 Maths subject.It will helps to get more idea about question pattern in every book back questions with solution.
Download Tamil Nadu 9th Standard Maths question papers, model tests, one-mark questions, important questions, and public exam papers in PDF format. Free study materials and answer keys for TN State Board students.
Questions + Answers key
Take MCQ Maths Test1.
What are the coordinates of B if point P(−2, 3) divides the line segment joining A(−3, 5) and B internally in the ratio 1 : 6?
2.
In what ratio does the point P(–2, 4) divide the line segment joining the points A(–3, 6) and B(1, –2) internally?
3.
Find the points of trisection of the line segment joining (−2, −1) and (4, 8)
4.
The mid-points of the sides of a triangle are (5, 1), (3, −5) and (−5, −1). Find the coordinates of the vertices of the triangle.
5.
Plot the points A( 1, 0), B ( -7, 2), C (-3, 7) on a graph sheet and join them to form a triangle.
Plot the point G ( -3, 3).
Join AG and extend it to intersect BC at D.
Join BG and extend it to intersect AC at E.
What do you infer when you measure the distance between BD and DC and the distance between CE and EA?
Using distance formula find the lengths of CG and GF, where F in on AB.
Write your inference about AG: GD, BG: GE and CG: GF.
6.
(i) Where do the following points lie?
P (0, -4), Q(0, -1), R(0, 3), S(0, 6).
(ii) Find the distance between the following points using coordinates given in question
(a) P and R
(b) Q and S
(iii) Draw the line diagram for the given above points.
7.
A(–1, 1), B(1, 3) and C(3, a) respectively and if AB = BC, then find ‘a’.
8.
Verify that the following points taken in order form the vertices of a rhombus.
A (1, 1), B(2, 1),C (2, 2) and D(1, 2)
9.
Verify that the following points taken in order form the vertices of a rhombus.
A(3, –2), B (7, 6),C (–1, 2) and D (–5, –6)
10.
Show that (4, 3) is the centre of the circle passing through the points (9, 3), (7, –1), (–1, 3). Find the radius.
1.
Let A(−3, 5) and B(x2, y2 ) be the given two points.
Given P(−2, 3) divides AB internally in the ratio 1:6.
By section formula, P\(\left( \frac { m{ x }_{ 2 }+n{ x }_{ 1 } }{ m+n } ,\frac { m{ y }_{ 2 }+n{ y }_{ 1 } }{ m+n } \right) \) = P(-2, 3)
P\(\left( \frac { 1({ x }_{ 2 })+6(-33) }{ 1+6 } ,\frac { 1({ y }_{ 2 })+6(5) }{ 1+6 } \right) \) = P(-2, 3)
Equating the coordinates
\(\frac { { x }_{ 2 }-18 }{ 7 } \) = -2
x2 −18 = −14
x2 = 4
\(\frac { { y }_{ 2 }-30 }{ 7 } \) = 3
y2 + 30 = 21
y2 = −9
Therefore, the coordinate of B is (4, −9)
2.
Given points are A(–3, 6) and B(1, –2), P(–2, 4) divide AB internally in the ratio m : n.
By section formula,
\(P(x, y)=P\left(\frac{m x_{2}+n x_{1}}{m+n}, \frac{m y_{2}+n y_{1}}{m+n}\right)\)
= P(−2, 4) .......(1)
Here x1 = −3, y1 = 6, x2 = 1, y2 = −2
\((1)\Rightarrow \left( \frac { m(1)+n(-3) }{ m+n } ,\frac { m(-2)+n(6) }{ m+n } \right) \)
Equating x-coordinates, we get
\(\frac{m-3 n}{m+n}=-2\) or m− 3n = −2m− 2n
3m = n
\(\frac{m}{n}=\frac{1}{3}\)
m : n = 1: 3
Hence P divides AB internally in the ratio 1 : 3.
3.
Let A(−2, −1) and B(4, 8) are the given points.
Let P(a,b) and Q(c,d) be the points of trisection of AB, so that AP = PQ = QB .
By the formula proved above,
P is the point.
\(\left( \frac { { x }_{ 2 }+{ 2x }_{ 1 } }{ 3 } ,\frac { { y }_{ 2 }+{ 2y }_{ 1 } }{ 3 } \right) =\left( \frac { 4+2(-2) }{ 3 } ,\frac { 8+2(-1) }{ 3 } \right) \) = (0, 2)
Q is the point
\(\left( \frac { { 2x }_{ 2 }+{ x }_{ 1 } }{ 3 } ,\frac { {2 y }_{ 2 }+{ y }_{ 1 } }{ 3 } \right) =\left( \frac { 2(4)-2 }{ 3 } ,\frac { 2(8)-1 }{ 3 } \right) \) = (2, 5)
4.
Let the vertices of the ABC be A(x1, y1), B(x2, y2 ) and C(x3, y3) and the given mid-points of the sides AB, BC and CA are (5, 1), (3, −5) and (−5, −1) respectively. Therefore
\(\frac { { x }_{ 1 }+{ x }_{ 2 } }{ 2 } =5 \Rightarrow\)x1 + x2 = 10 ...(1)
\(\frac { { x }_{ 2 }+{ x }_{ 3 } }{ 2 } =3 \Rightarrow\)x2 + x3 = 6 ...(2)
\(\frac { { x }_{ 3 }+{ x }_{ 1 } }{ 2 } =-5 \Rightarrow\)x3 + x1 = –10 ...(3)
Adding (1), (2) and (3)
2x1 + 2x2 + 2x3 = 6
x1 + x2 + x3 = 3 ...(4)
(4) − (2) \(\Rightarrow\) x1 = 3 − 6 = −3
(4) − (3) \(\Rightarrow\) x2 = 3 +10 = 13
(4) − (1) \(\Rightarrow\) x3 = 3 −10 = −7
\(\frac { { y }_{ 1 }+{ y }_{ 2 } }{ 2 } =1\)\(\Rightarrow\)y1 + y2 = 2 …(5)
\(\frac { { y }_{ 2 }+{ y }_{ 3 } }{ 2 } =-5\)\(\Rightarrow\)y2 + y3 = –10 …(6)
\(\frac { { y }_{ 3 }+{ y }_{ 1 } }{ 2 } =1\)\(\Rightarrow\)y3 + y1 = –2 …(7)
Adding (5), (6) and (7),
2y1 + 2y2 + 2y3 = −10
y1 + y2 + y3 = −5 ...(8)
(8) − (6) \(\Rightarrow\) y1 = −5 +10 = 5
(8) − (7) \(\Rightarrow\) y2 = −5 + 2 = −3
(8) − (5) \(\Rightarrow\) y3 = −5 − 2 = −7
Therefore the vertices of the triangles are A(−3, 5), B(13, −3) and C(−7, −7).
5.

Measure BD and DC.
BD = 3.3 cm and DC = 3.3 cm
\(\therefore\) BD=DC=3.3 cm
Measure CE and EA.
CE =4 cm andEA= 4 cm
\(\therefore\) CE=EA=4cm
Distance =\(\sqrt{(x_2+x_1)^2+(y_2-y_1)^2}\)
CG =\(\sqrt{(-3+3)^2+(3-7)^2}\)
\(=\sqrt{0+(-4)^2}=\sqrt{16}=4 \ uints\)
GF =\(\sqrt{(-3+3)^2+(3-1)^2}\) (The point F is (-3,1) )
\(=\sqrt{0+2^2}=\sqrt{4}=2 \ uints\)
AG =\(\sqrt{(-3-1)^2+(3-0)^2}\)
\(=\sqrt{(-4)^2+(3)^2}=\sqrt{16+9}=\sqrt{25}=5 \ units\)
GD =\(\sqrt{(-3+5)^2+(3-4.5)^2}\)
\(=\sqrt{2^2+(-1.5)^2}=\sqrt{4+2.25}=\sqrt{6.25}=2.5 \ uints\)
BG =\(\sqrt{(-7+3)^2+(2-3)^2}\)
\(=\sqrt{(-4)^2+(-1)^2}=\sqrt{16+1}\)
\(=\sqrt{17}=4.12 \ units\) (Approximately BG = 4)
GE =\(\sqrt{(-3+1)^2+(3-3.5)^2}\)
\(=\sqrt{2^2+(0.5)^2}=\sqrt{4+0.25}\)
\(=\sqrt{4.25}=2.06 \ units\) (Approximately GE = 2)
AG : GD = 5 : 2.5
= 1 : 0.5
=2: 1
BG: GE =4: 2
= 2: 1
CG: GF =4: 2
= 2: 1
AG : GD = BG : GE = CG = GF = 2 : 1
6.
(i) The point P (0, -4), Q(0, -1), R(0, 3), S(0, 6) lies on the y-axis.
(ii) Distance = \(\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}\)
(a) PR=\(\sqrt{(0-0)^2+(3+4)^2}\)
\(=\sqrt{0+7^2}=\sqrt{49}=7 \ uint\)
(b) QS =\(\sqrt{(0-0)^2+(6+1)^2}\)
\(=\sqrt{0+7^2}=\sqrt{49}=7 \ uint\)

7.
(-1,1), (1, 3) and (3, a)
Distance =\(\sqrt { ({ x }_{ 2 }-{ x }_{ 1 })^{ 2 }+({ y }_{ 2 }-y_{ 1 })^{ 2 } } \)
AB =\(\sqrt { (1+1)^{ 2 }+(3-1)^{ 2 } } \)
= \(\sqrt { (2)^{ 2 }+(2)^{ 2 } } =\sqrt { 4+4 } =\sqrt { 8 } \)
BC =\(\sqrt { (3-1)^{ 2 }+(a-3)^{ 2 } } \)
= \(\sqrt { (2)^{ 2 }+(a-3)^{ 2 } } =\sqrt { 4+(a-3)^{ 2 } } \)
But given AB = BC ⇒\(\sqrt { 8 } =\sqrt { 4+(a-3)^{ 2 } } \)
a-3 = 2 (or) a - 3 = -2
a = 2+3 (or) a = 3-2
a = 5 (or) a = 1
∴ 4+(a - 3)2 = 8
(a - 3)2 = 8 - 4
(a - 3)2 = 4
a - 3 = \(\sqrt { 4 } =\pm 2\)
∴ The value of a = 5 or a = 1
8.
Distance = \(\sqrt { ({ x }_{ 2 }-{ x }_{ 1 })^{ 2 }+(y_{ 2 }-y_{ 1 })^{ 2 } } \)
AB = \(\sqrt { (2-1)^{ 2 }+(1-1)^{ 2 } } \)
= \(\sqrt { (1)^{ 2 }+(0)^{ 2 } } =\sqrt { 1 } =1\)
BC = \(\sqrt { (2-1)^{ 2 }+(2-1)^{ 2 } } \)
= \(\sqrt { (0)^{ 2 }+(1)^{ 2 } } =\sqrt { 1 } =1\)
CD =\(\sqrt { (1-2)^{ 2 }+(2-2)^{ 2 } } \)
= \(\sqrt { (-1)^{ 2 }+(0)^{ 2 } } =\sqrt { 1 } =1\)
AD =\(\sqrt { (1-1)^{ 2 }+(2-1)^{ 2 } } \)
= \(\sqrt { (0)^{ 2 }+(1)^{ 2 } } =\sqrt { 1 } =1\)
AB = BC = CD = AD =1
All the four sides are equal.
ABCD is a rhombus
9.
Distance =\(\sqrt { ({ x }_{ 2 }-{ x }_{ 1 })^{ 2 }+(y_{ 2 }-y_{ 1 })^{ 2 } } \)
AB = \(\sqrt { (7-3)^{ 2 }+(6+2)^{ 2 } } =\sqrt { (4)^{ 2 }+(8)^{ 2 } } \)
= \(\sqrt { 16+64 } =\sqrt { 80 } \)
BC = \(\sqrt { (-1-7)^{ 2 }+(2-6)^{ 2 } } =\sqrt { (-8)^{ 2 }+(-4)^{ 2 } } \)
= \(\sqrt { 64+16 } =\sqrt { 80 } \)
CD = \(\sqrt { (-5+1)^{ 2 }+(-6-2)^{ 2 } } =\sqrt { (-4)^{ 2 }+(-8)^{ 2 } } \)
= \(\sqrt { 16+64 } =\sqrt { 80 } \)
AD =\(\sqrt { (-5-3)^{ 2 }+(-6-2)^{ 2 } } =\sqrt { (-8)^{ 2 }+(-4)^{ 2 } } \)
= \(\sqrt { 64+16 } =\sqrt { 80 } \)
AB = BC = CD = AD = \(\sqrt { 80 } \)
All the four sides are equal
∴ ABCD is a rhombus
10.
Let P(4, 3), A(9, 3), B(7, –1) and C(–1, 3)
If P is the centre of the circle which passes through the points A, B, and C, then P is equidistant from A, B and C (i.e.) PA = PB = PC
By distance formula,
\(d=\sqrt{(x_2 -x_1)^2 +(y_2 -y_1)^2}\)
\(AP=PA =\sqrt{(4-9)^2+(3-3)^2}=\sqrt{(-5)^2+0}=\sqrt{25}=5\)
\(BP=PB =\sqrt{(4-7)^2+(3+1)^2}=\sqrt{(3)^2+(4)^2}=\sqrt{9+16}=\sqrt{25}=5\)
\(CP=CB =\sqrt{(4+1)^2+(3-3)^2}=\sqrt{(5)^2+0}=\sqrt{25}=5\)
PA = PB = PC, Radius = 5
Therefore P is the centre of the circle, passing through A, B and C
9th Standard Syllabus & Materials
9th Standard
TN 9th Tamil உள்ளத்தின் சீர் - திருக்குறள் Important Questions And Answers Study Material - QB365 Set A
NEW9th Standard
TN 9th Tamil உள்ளத்தின் சீர் - மணிமேகலை Important Questions And Answers Study Material - QB365 Set A
NEW9th Standard
TN 9th Tamil உள்ளத்தின் சீர் - ஏறு தழுவுதல் Important Questions And Answers Study Material - QB365 Set A
NEW9th Standard
TN 9th Tamil உயிருக்கு வேர் - தண்ணீர் Important Questions And Answers Study Material - QB365 Set A
Tamilnadu Stateboard 9th Standard Subjects
Tamilnadu Stateboard Standards