9th Standard Syllabus & Materials
9th Standard
TN 9роЖроорпН ро╡роХрпБрокрпНрокрпБ роХрогро┐родроорпН роЖропродрпНродрпКро▓рпИ ро╡роЯро┐ро╡ро┐ропро▓рпН,роорпБроХрпНроХрпЛрогро╡ро┐ропро▓рпН роорпБроХрпНроХро┐ропрооро╛рой 2,3,&5 роородро┐рокрпНрокрпЖрогрпН ро╡ро┐ройро╛роХрпНроХро│рпН ро╡ро┐роЯрпИроХро│рпБроЯройрпН TN 9th Maths Coordinate Geometry,Trigonometry Important 1 Mark Questions with Answers 2,3,&5 Marks Questions with Answers
NEW9th Standard
TN 9роЖроорпН ро╡роХрпБрокрпНрокрпБ роХрогро┐родроорпН роЕро│ро╡ро┐ропро▓рпН,рокрпБро│рпНро│ро┐ропро┐ропро▓рпН&роиро┐роХро┤рпНродроХро╡рпБ роорпБроХрпНроХро┐ропрооро╛рой 2,3,&5 роородро┐рокрпНрокрпЖрогрпН ро╡ро┐ройро╛роХрпНроХро│рпН ро╡ро┐роЯрпИроХро│рпБроЯройрпН TN 9th Maths Mensuration,Statistics&Probability Important 1 Mark Questions with Answers 2,3,&5 Marks Questions with Answers.
NEW9th Standard
TN 9роЖроорпН ро╡роХрпБрокрпНрокрпБ роЪроорпВроХ роЕро▒ро┐ро╡ро┐ропро▓рпН ро╡ро░ро▓ро╛ро▒рпБ - роЪрпЖро╡рпНро╡ро┐ропро▓рпН роЙро▓роХроорпН роорпБроХрпНроХро┐ропрооро╛рой 2,3,&5 роородро┐рокрпНрокрпЖрогрпН ро╡ро┐ройро╛роХрпНроХро│рпН ро╡ро┐роЯрпИроХро│рпБроЯройрпН TN 9th Social Science HIS - The Classical World Important 1 Mark Questions with Answers 2,3,&5 Marks Questions with Answers.
NEW9th Standard
TN 9роЖроорпН ро╡роХрпБрокрпНрокрпБ роЪроорпВроХ роЕро▒ро┐ро╡ро┐ропро▓рпН ро╡ро░ро▓ро╛ро▒рпБ - родрпКроЯроХрпНроХроХро╛ро▓родрпН родрооро┐ро┤рпНроЪрпН роЪроорпВроХроорпБроорпН рокрогрпНрокро╛роЯрпБроорпНроорпБроХрпНроХро┐ропрооро╛рой 2,3,&5 роородро┐рокрпНрокрпЖрогрпН ро╡ро┐ройро╛роХрпНроХро│рпН ро╡ро┐роЯрпИроХро│рпБроЯройрпН TN 9th Social Science HIS - Early Tamil Society and Culture Important 1 Mark Questions with Answers 2,3,&5 Marks Questions with Answers.
NEW9th Standard
TN 9роЖроорпН ро╡роХрпБрокрпНрокрпБ роЪроорпВроХ роЕро▒ро┐ро╡ро┐ропро▓рпН ро╡ро░ро▓ро╛ро▒рпБ - родрпКро┤ро┐ро▒рпНрокрпБро░роЯрпНроЪро┐ роорпБроХрпНроХро┐ропрооро╛рой 2,3,&5 роородро┐рокрпНрокрпЖрогрпН ро╡ро┐ройро╛роХрпНроХро│рпН ро╡ро┐роЯрпИроХро│рпБроЯройрпН TN 9th Social Science HIS - Industrial Revolution Important 1 Mark Questions with Answers 2,3,&5 Marks Questions with Answers.
NEW9th Standard
TN 9роЖроорпН ро╡роХрпБрокрпНрокрпБ роЪроорпВроХ роЕро▒ро┐ро╡ро┐ропро▓рпН ро╡ро░ро▓ро╛ро▒рпБ - роиро╡рпАрой ропрпБроХродрпНродро┐ройрпН родрпКроЯроХрпНроХроорпН роорпБроХрпНроХро┐ропрооро╛рой 2,3,&5 роородро┐рокрпНрокрпЖрогрпН ро╡ро┐ройро╛роХрпНроХро│рпН ро╡ро┐роЯрпИроХро│рпБроЯройрпН TN 9th Social Science HIS - The Beginning of the Modern AgeImportant 1 Mark Questions with Answers 2,3,&5 Marks Questions with Answers.

Published on: 13/05/2022
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.
latest Book back QuestionsDownload 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.
Find the coordinates of the point which divides the line segment joining A(−5,11) and B(4,−7) in the ratio 7:2.
2.
Find the coordinates of a point P on the line segment joining A(1, 2) and B(6, 7) in such a way that AP = \(\frac{2}{5}\)AB
3.
The line segment joining A(6, 3) and B(−1, −4) is doubled in length by adding half of AB to each end. Find the coordinates of the new end points.
4.
Using section formula, show that the points A(7, −5), B(9, −3) and C(13, 1) are collinear.
5.
A line segment AB is increased along its length by 25% by producing it to C on the side of B. If A and B have the coordinates (−2,−3) and (2,1) respectively, then find the coordinates of C.
6.
If the centroid of a triangle is at (4, −2) and two of its vertices are (3, −2) and (5, 2) then find the third vertex of the triangle.
7.
The vertices of a triangle are (1, 2), (h, −3) and (−4, k). If the centroid of the triangle is at the point (5, −1) then find the value of \(\sqrt { { (h+k) }^{ 2 }+{ (h+3k) }^{ 2 } } \)
8.
Orthocentre and centroid of a triangle are A(−3, 5) and B(3,3) respectively. If C is the circumcentre and AC is the diameter of this cicle, then find the radius of the circle.
9.
ABC is a triangle whose vertices are A(3, 4), B(−2, −1) and C(5, 3) . If G is the centroid and BDCG is a parallelogram then find the coordinates of the vertex D.
10.
If \(\left( \frac { 3 }{ 2 } ,5 \right) ,\left( 7,\frac { -9 }{ 2 } \right) \)and\((\frac{13}{2},\frac{-13}{2})\) are mid-points of the sides of a triangle, then find the centroid of the triangle.
1.

x1 y1
Here (-5,11)
x2 y2
(4,-7)
m n
7 : 2
\(=P(x,y)\left( \frac { { mx }_{ 2 }+{ nx }_{ 1 } }{ m+n } ,\frac { { my }_{ 2 }+{ ny }_{ 1 } }{ m+n } \right) \)
\(=\left( \frac { 7\times 4+2\times -5 }{ 7+2 } ,\frac { 7\times -7+2\times 11) }{ 7+2 } \right) \)
\(=\left( \frac { 28-10 }{ 9 } ,\frac { -49+22 }{ 9 } \right) \)
\(=\left( \frac { 18 }{ 9 } ,\frac { -27 }{ 9 } \right) =(2,-3)\)
2.

x1 y1 x2 y2
A(1, 2) B (6, 7)
\(=P(x,y)\left( \frac { { mx }_{ 2 }+{ nx }_{ 1 } }{ m+n } ,\frac { { my }_{ 2 }+{ ny }_{ 1 } }{ m+n } \right) \)
\(=\left( \frac { 2\times 6+3\times 1 }{ 2+3 } ,\frac { 2\times 7+3\times 2) }{ 2+3 } \right) \)
\(=\left( \frac { 12-3 }{ 5 } ,\frac { 14+6 }{ 5 } \right) =\left( \frac { 15 }{ 5 } ,\frac { 20 }{ 5 } \right) =(3,4)\)
3.

\(\bar { AB } =\sqrt { { ({ x }_{ 2 }-{ x }_{ 1 }) }^{ 2 }+{ ({ y }_{ 2 }-{ y }_{ 1 }) }^{ 2 } } =\sqrt { { (-1-6) }^{ 2 }+{ (-4-3) }^{ 2 } } \)
\(=\sqrt { { (-7) }^{ 2 }+{ (-7) }^{ 2 } } =\sqrt { 49+49 } =\sqrt { (49)2 } \)
\(\frac { 1 }{ 2 } AB=\frac { 7\sqrt { 2 } }{ 2 } =\frac { 7\sqrt { 2 } }{ \sqrt { 2 } \times \sqrt { 2 } } =\frac { 7 }{ \sqrt { 2 } } \)
\(AB=\left( \frac { 6+(-1) }{ 2 } ,\frac { 3+(-4) }{ 2 } \right) =\left( \frac { 5 }{ 2 } ,\frac { -1 }{ 2 } \right) \)
Mid point of \(AB=\left( \frac { 6+(-1) }{ 2 } ,\frac { 3+(-4) }{ 2 } \right) =\left( \frac { 5 }{ 2 } ,\frac { -1 }{ 2 } \right) \)
SinceC is at the distance \(\frac{1}{2}\) AB from B
Midpoint of MC = B
\(\left( \frac { \frac { 5 }{ 2 } +{ x }_{ 3 } }{ 2 } ,\frac { \frac { -1 }{ 2 } +{ y }_{ 3 } }{ 2 } \right) =(-1,-4)\)
\(\left( \frac { \frac { 5 }{ 2 } +{ x }_{ 3 } }{ 2 } \right) =-1\)
\(\frac { 5 }{ 2 } +{ x }_{ 3 }=-2\)
\({ x }_{ 3 }=-2-\frac { 5 }{ 2 } \)
\(=\frac { -4-5 }{ 2 } \)
\(=\frac { -9 }{ 2 } \)
\(\therefore C({ x }_{ 3 },{ y }_{ 3 })=\left( \frac { -9 }{ 2 } ,\frac { -15 }{ 2 } \right) \)
\(\left( \frac { -\frac { 1 }{ 2 } +{ y }_{ 3 } }{ 2 } \right) =-4\)
|\(-\frac { 1 }{ 2 } +{ y }_{ 3 }=-8\)
\({ y }_{ 3 }=-8+\frac { 1 }{ 2 } \)
\(=\frac { -16+1 }{ 2 } \)
\(=\frac { -15 }{ 2 } \)
Similarly by Mid point of DM = A(6, 3)
\(\left( \frac { { x }_{ 4 }+\frac { 5 }{ 2 } }{ 2 } ,\frac { { y }_{ 4 }+\left( \frac { -1 }{ 2 } \right) }{ 2 } \right) =(6,3)\)
\(\frac { { x }_{ 4 }+\frac { 5 }{ 2 } }{ 2 } =6\)
\({ x }_{ 4 }+\frac { 5 }{ 2 } =12\)
\({ x }_{ 4 }=12-\frac { 5 }{ 2 } =\frac { 24-5 }{ 2 } =\frac { 19 }{ 2 } \)
\(\frac { { y }_{ 4 }+\left( \frac { -1 }{ 2 } \right) }{ 2 } =3\)
\({ y }_{ 4 }+\left( \frac { -1 }{ 2 } \right) =6\)
\({ y }_{ 4 }=6+\frac { 1 }{ 2 } =\frac { 12+102 }{ 2 } =\frac { 13 }{ 2 } \)
\(\therefore\) The other end D (x4, y4)\(=\left( \frac { 19 }{ 2 } ,\frac { 13 }{ 2 } \right) \)
4.
x1 y1 x2 y2
A(7, -5) B(9, -3)
\(\bar { AB } =\sqrt { { ({ x }_{ 2 }-{ x }_{ 1 }) }^{ 2 }+{ ({ y }_{ 2 }-{ y }_{ 1 }) }^{ 2 } } \)
\(=\sqrt { { (9-7) }^{ 2 }+{ (-3-(-5)) }^{ 2 } } =\sqrt { { 2 }^{ 2 }+{ (-3+5) }^{ 2 } } =\sqrt { 4+4 } \)
\(=\sqrt { 8 } =\sqrt { 4\times 2 } =2\sqrt { 2 } \)
\(\bar { BC } =\sqrt { { (13-7 })^{ 2 }+{ (1-(-5)) }^{ 2 } } =\sqrt { { 4 }^{ 2 }+{ 4 }^{ 2 } } =\sqrt { 16+16 } \)
\(=\sqrt { 32 } =\sqrt { 16\times 2 } =4\sqrt { 2 } \)
\(\bar { AC } =\sqrt { { (13-7) }^{ 2 }+{ (1-(-5)) }^{ 2 } } \)
\(=\sqrt { { 6 }^{ 2 }+{ 6 }^{ 2 } } =\sqrt { 36+36 } \)
\(=\sqrt { { 6 }^{ 2 }+{ 6 }^{ 2 } } =\sqrt { 36+36 } \)
\(2\sqrt { 2 } +4\sqrt { 2 } =6\sqrt { 2 } \)
∴ AB + BC = AC, Here B is the common Point
∴ A, B, C are collinear
5.

x1 y1 x2 y2
A(-2, -3) B(2, 1)
m : n = 3 : 1
The point P divides AB in the ratio 3 : 1
\(P(x,y)=\left( \frac { { mx }_{ 2 }+{ nx }_{ 1 } }{ m+n } ,\frac { { my }_{ 2 }+{ ny }_{ 1 } }{ m+n } \right) \)
\(=\left( \frac { 3\times 2+1\times -2 }{ 3+1 } ,\frac { 3\times 1+1\times -3) }{ 3+1 } \right) \)
\(=\left( \frac { 6-2 }{ 4 } ,\frac { 3-3 }{ 4 } \right) =\left( \frac { 4 }{ 4 } ,\frac { 0 }{ 4 } \right) =(1,0)\)
P is at 25% distance from B on its left and C is at 25% distance from B on its right
\(\therefore\) B is the mid point of PC
Mid point of \(\bar { PC } =\left( \frac { { x }_{ 1 }+{ x }_{ 2 } }{ 2 } ,\frac { { y }_{ 1 }+{ y }_{ 2 } }{ 2 } \right) \)
\((2,1)=\left( \frac { 1+{ x }_{ 2 } }{ 2 } ,\frac { 0+{ y }_{ 2 } }{ 2 } \right) \)
\(\frac { 1+{ x }_{ 2 } }{ 2 } =2\quad \frac { { y }_{ 2 } }{ 2 } =1\)
1 + x2 = 4 y2 = 2
⇒ x2 = 3, y2 = 2
∴ C(x2, y2) = (3, 2) is the solutions.
6.
Centroid G (x,y) = (4, -2)
two vertices (x1, y1) = (3, -2)
(x2, y2) = (5, 2), (x3, y3) =?

\(\frac { 8+{ x }_{ 3 } }{ 3 } =4\ \ \frac { { y }_{ 3 } }{ 3 } =-2\)
8 + x3 = 12 y3 = -6
x3 = 4
∴ The third vertex (x3, y3) = (4, -6)
7.
Vertices of a triangle
(x1 ,y1) = (1,2)
(x2,y2) = (h,-3)
(x3, y3) = (-4, k)
Centroid G (x,y) = (5, -1)
\(G=\left( \frac { { x }_{ 1 }+{ x }_{ 2 }+{ x }_{ 3 } }{ 3 } ,\frac { { y }_{ 1 }+{ y }_{ 2 }+{ y }_{ 3 } }{ 3 } \right) =(5,-1)\)
\(\left( \frac { 1+h+(-4) }{ 3 } ,\frac { 2+(-3)+k }{ 3 } \right) =(5,-1)\)
\(\Rightarrow \frac { -3+h }{ 3 } =5\)
-3 + h = 15
h = 18
\(\frac { 2-3+k }{ 3 } =-1\)
\(\therefore \sqrt { { (h+k) }^{ 2 }+{ (h+3k) }^{ 2 } } \)
\(=\sqrt { (18+(-2))^{ 2 }+{ (18+3(-2)) }^{ 2 } } \)
\(=\sqrt { { 16 }^{ 2 }+{ 12 }^{ 2 } } =\sqrt { 256+144 } =\sqrt { 400 } =20\)
8.
H = A (-3, 5)
G = B (3, 3)
S = Circumcentre (C)
G divides Hand S in the ratio 2 :1


m : n = 1 : 2
A(x2, y1) = (-3, 5)
C(x2, y2) = (x2, y2)
P (x, y) = (3, 3)
\(\therefore \ P(x,y)=\left( \frac { { mx }_{ 2 }+{ nx }_{ 1 } }{ m+n } ,\frac { { my }_{ 2 }+{ ny }_{ 1 } }{ m+n } \right) \)
\((3,3)=\left( \frac { { 1x }^{ 2 }+2(3) }{ 2+1 } ,\frac { 1({ y }_{ 2 })+2(5) }{ 2+1 } \right) \)
\((3,3)=\left( \frac { { x }_{ 2 }-6 }{ 3 } ,\frac { { y }_{ 2 }+10 }{ 3 } \right) \)
\(\frac { { x }_{ 2 }-6 }{ 3 } =3\)
x2 - 6 = 9
x2 = 9 + 6
x = 15
\(\frac { { y }_{ 2 }+10 }{ 3 } =3\)
y2+10 = 9
y2 = 9-10
y2 = -1
\(\bar { AC } =\sqrt { { (5-(-3)) }^{ 2 }+{ (-1-5) }^{ 2 } } \)
\(=\sqrt { { 8 }^{ 2 }+{ (-6) }^{ 2 } } =\sqrt { 324+36 } \)
\(=\sqrt { 360 } =\sqrt { 36\times 10 } =6\sqrt { 10 } \)
radius = \(\frac{1}{2}\)AC
\(=\frac { 1 }{ 2 } \times 6\sqrt { 10 } =3\sqrt { 10 } \)units.
Radius \(=\frac{3}{2} \sqrt{10}\) or \(3 \sqrt{\frac{10}{4}}\)
\(=3 \sqrt{\frac{5}{2}}\) units
\(\because \) AC is a diametre of circle
9.

Centroid G =\(\left( \frac { { x }_{ 1 }+{ x }_{ 2 }+{ x }_{ 3 } }{ 3 } ,\frac { { y }_{ 1 }+{ y }_{ 2 }+{ y }_{ 3 } }{ 3 } \right) \)
\(\therefore G(x,y)=\left( \frac { 3+(-2)+5 }{ 3 } ,\frac { 4+(-1)+3 }{ 3 } \right) \)
\(=\left( \frac { 8-2 }{ 3 } ,\frac { 7-1 }{ 3 } \right) =\left( \frac { 6 }{ 3 } ,\frac { 6 }{ 3 } \right) =(2,2)\)
In a parallelogram diagonals bisect each other
∴ Mid point of DG = Mid point of BC
\(\left( \frac { x+2 }{ 2 } ,\frac { y+2 }{ 2 } \right) =\left( \frac { -2+5 }{ 2 } ,\frac { -1+3 }{ 2 } \right) \)
\(\frac { x+2 }{ 2 } =\frac { 3 }{ 2 } \)
x+2 = 3
x = 3 - 2 = 1
\(\frac { y+2 }{ 2 } =\frac { 2 }{ 2 } \)
y = 2 - 2 = 0
y + 2 = 2
\(\therefore\) The co-ordinates of the vertex D (x, y) = (1, 0)
10.
"The centroid of the triangle obtained by joining the mid points of the sides of a triangle is the same as the centroid of the original triangle."
\(\therefore\) The mid points of the sides of the triangle are given as
x1y1 , x2y, x3y3
\(\left( \frac { 3 }{ 2 } ,5 \right) \left( 7,\frac { -9 }{ 2 } \right) \left( \frac { 13 }{ 2 } ,\frac { -13 }{ 2 } \right) \)
\(\therefore\)Centroid \(=\left( \frac { { x }_{ 1 }+{ x }_{ 2 }+{ x }_{ 3 } }{ 3 } ,\frac { { y }_{ 1 }+{ y }_{ 2 }+{ y }_{ 3 } }{ 3 } \right) \)
\(=\left( \frac { \frac { 3 }{ 2 } +\frac { 7 }{ 1 } +\frac { 13 }{ 2 } }{ 3 } ,\frac { 5+\left( \frac { -9 }{ 2 } \right) +\frac { (-13) }{ 2 } }{ 3 } \right) =\left( \frac { \frac { 3+14+13 }{ 2 } }{ 3 } ,\frac { \frac { 10-9-13 }{ 2 } }{ 3 } \right) \)
\(=\left( \frac { \frac { 30 }{ 2 } }{ 3 } ,\frac { \frac { -12 }{ 2 } }{ 3 } \right) =\left( \frac { 15 }{ 3 } ,\frac { -6 }{ 3 } \right) =(5,-2)\)
9th Standard Syllabus & Materials
9th Standard
TN 9роЖроорпН ро╡роХрпБрокрпНрокрпБ роЪроорпВроХ роЕро▒ро┐ро╡ро┐ропро▓рпН ро╡ро░ро▓ро╛ро▒рпБ - рокрогрпНроЯрпИроп роиро╛роХро░ро┐роХроЩрпНроХро│рпН роорпБроХрпНроХро┐ропрооро╛рой 2,3,&5 роородро┐рокрпНрокрпЖрогрпН ро╡ро┐ройро╛роХрпНроХро│рпН ро╡ро┐роЯрпИроХро│рпБроЯройрпН TN 9th Social Science HIS - Ancient . Civilisations Important 1 Mark Questions with Answers 2,3,&5 Marks Questions with Answers.
NEW9th Standard
TN 9роЖроорпН ро╡роХрпБрокрпНрокрпБ роЪроорпВроХ роЕро▒ро┐ро╡ро┐ропро▓рпН ро╡ро░ро▓ро╛ро▒рпБ - рокрпБро░роЯрпНроЪро┐роХро│ро┐ройрпН роХро╛ро▓роорпН роорпБроХрпНроХро┐ропрооро╛рой 2,3,&5 роородро┐рокрпНрокрпЖрогрпН ро╡ро┐ройро╛роХрпНроХро│рпН ро╡ро┐роЯрпИроХро│рпБроЯройрпН TN 9th Social Science HIS - The Age of Revolutions Important 1 Mark Questions with Answers 2,3,&5 Marks Questions with Answers.
NEW9th Standard
TN 9роЖроорпН ро╡роХрпБрокрпНрокрпБ роЪроорпВроХ роЕро▒ро┐ро╡ро┐ропро▓рпН ро╡ро░ро▓ро╛ро▒рпБ - роЗроЯрпИроХрпНроХро╛ро▓ роЗроирпНродро┐ропро╛ро╡ро┐ро▓рпН роЕро░роЪрпБроорпН роЪроорпВроХроорпБроорпН роорпБроХрпНроХро┐ропрооро╛рой 2,3,&5 роородро┐рокрпНрокрпЖрогрпН ро╡ро┐ройро╛роХрпНроХро│рпН ро╡ро┐роЯрпИроХро│рпБроЯройрпН TN 9th Social Science HIS - State and Society in Medieval India Important 1 Mark Questions with Answers 2,3,&5 Marks Questions with Answers.
NEW9th Standard
TN 9роЖроорпН ро╡роХрпБрокрпНрокрпБ роЪроорпВроХ роЕро▒ро┐ро╡ро┐ропро▓рпН ро╡ро░ро▓ро╛ро▒рпБ - роЖроЪро┐роп роЖрокрпНрокро┐ро░ро┐роХрпНроХ роиро╛роЯрпБроХро│ро┐ро▓рпН роХро╛ро▓ройро┐ропро╛родро┐роХрпНроХроорпН роорпБроХрпНроХро┐ропрооро╛рой 2,3,&5 роородро┐рокрпНрокрпЖрогрпН ро╡ро┐ройро╛роХрпНроХро│рпН ро╡ро┐роЯрпИроХро│рпБроЯройрпН TN 9th Social Science HIS - Colonialism in Asia and Africa Important 1 Mark Questions with Answers 2,3,&5 Marks Questions with Answers.
Tamilnadu Stateboard 9th Standard Subjects
Tamilnadu Stateboard Standards