Class IX 2008
Class IX (Matemetics)
Time : 3 Hours
Marks : 80
STATISTICS AND PROBABILITY
UNIT I : NUMBER SYSTEMS
1. REAL NUMBERS (20)
Review of representation of natural numbers, integers, rational numbers on the
number line. Representation of terminating / non-terminating recurring decimals,
on the number line through successive magnification. Rational numbers as
Examples of nonrecurring / non terminating decimals such as Ö2,
Ö3, Ö5 etc. Existence of
non-rational numbers (irrational numbers) such as Ö2,
Ö3 and their representation on the number line.
Explaining that every real number is represented by a unique point on the number
line and conversely, every point on the number line represents a unique real
Existence of Öx for a given positive real number x
(visual proof to be emphasized).
Definition of nth root of a real number.
Recall of laws of exponents with integral powers. Rational exponents with
positive real bases (to be done by particular cases, allowing learner to arrive
at the general laws.)
Rationalization (with precise meaning) of real numbers of the type (& their
___1___ & __1___ where x and y are natural
number and a, b are integers.
a + bÖx Öx
UNIT II : ALGEBRA
Definition of a polynomial in one variable, its coefficients, with examples and
counter examples, its terms, zero polynomial. Degree of a polynomial. Constant,
linear, quadratic, cubic polynomials; monomials, binomials, trinomials. Factors
and multiples. Zeros/roots of a polynomial / equation. State and motivate the
Remainder Theorem with examples and analogy to integers. Statement and proof of
the Factor Theorem. Factorization of ax2 + bx + c, a ¹
0 where a, b, c are real numbers, and of cubic polynomials using the Factor
Recall of algebraic expressions and identities. Further
identities of the type (x + y + z)2 = x2 + y2 +
z2 + 2xy + 2yz + 2zx, (x ± y)3
= x3 ± y3 ±
3xy (x ± y).
x3 + y3 + z3 – 3xyz = (x + y + z) (x2
+ y2 + z2 – xy – yz – zx) and their use in
factorization of polymonials. Simple expressions reducible to these polynomials.
2. LINEAR EQUATIONS IN TWO VARIABLES
( 12) Periods
Recall of linear equations in one variable. Introduction to the equation in two
variables. Prove that a linear equation in two variables has infinitely many
solutions and justify their being written as ordered pairs of real numbers,
plotting them and showing that they seem to lie on a line. Examples, problems
from real life, including problems on Ratio and Proportion and with algebraic
and graphical solutions being done simultaneously.
UNIT III : COORDINATE GEOMETRY
1. COORDINATE GEOMETRY
The Cartesian plane, coordinates of a point, names and terms associated with the
coordinate plane, notations, plotting points in the plane, graph of linear
equations as examples; focus on linear equations of the type ax + by + c = 0 by
writing it as y = mx + c and linking with the chapter on linear equations in two
UNIT IV : GEOMETRY
1. INTRODUCTION TO EUCLID'S GEOMETRY (6)
History - Euclid and geometry in India. Euclid's method of
formalizing observed phenomenon into rigorous mathematics with definitions,
common/obvious notions, axioms/postulates and theorems. The five postulates of
Euclid. Equivalent versions of the fifth postulate. Showing the relationship
between axiom and theorem.
1. Given two distinct points, there exists one and only one line through them.
2. (Prove) two distinct lines cannot have more than one point in common.
2. LINES AND ANGLES (10)
1. (Motivate) If a ray stands on a line, then the sum of the two adjacent angles
so formed is 180o and the converse.
2. (Prove) If two lines intersect, the vertically opposite angles are equal.
3. (Motivate) Results on corresponding angles, alternate angles, interior angles
when a transversal intersects two parallel lines.
4. (Motivate) Lines, which are parallel to a given line, are parallel.
5. (Prove) The sum of the angles of a triangle is 180o.
6. (Motivate) If a side of a triangle is produced, the exterior angle so formed
is equal to the sum of the two interiors opposite angles.
3. TRIANGLES (20)
1. (Motivate) Two triangles are congruent if any two sides and the included
angle of one triangle is equal to any two sides and the included angle of the
other triangle (SAS Congruence).
2. (Prove) Two triangles are congruent if any two angles and the included side
of one triangle is equal to any two angles and the included side of the other
triangle (ASA Congruence).
3. (Motivate) Two triangles are congruent if the three sides of one triangle are
equal to three sides of the other triangle (SSS Congruene).
4. (Motivate) Two right triangles are congruent if the hypotenuse and a side of
one triangle are equal (respectively) to the hypotenuse and a side of the other
5. (Prove) The angles opposite to equal sides of a triangle are equal.
6. (Motivate) The sides opposite to equal angles of a triangle are equal.
7. (Motivate) Triangle inequalities and relation between 'angle and facing side'
inequalities in triangles.
4. QUADRILATERALS (10)
1. (Prove) The diagonal divides a parallelogram into two congruent triangles.
2. (Motivate) In a parallelogram opposite sides are equal, and conversely.
3. (Motivate) In a parallelogram opposite angles are equal, and conversely.
4. (Motivate) A quadrilateral is a parallelogram if a pair of its opposite sides
is parallel and equal.
5. (Motivate) In a parallelogram, the diagonals bisect each other and
6. (Motivate) In a triangle, the line segment joining the mid points of any two
sides is parallel to the third side and (motivate) its converse.
Review concept of area, recall area of a rectangle.
1. (Prove) Parallelograms on the same base and between the same parallels have
the same area.
2. (Motivate) Triangles on the same base and between the same parallels are
equal in area and its converse.
Through examples, arrive at definitions of circle related concepts, radius,
circumference, diameter, chord, arc, subtended angle.
1. (Prove) Equal chords of a circle subtend equal angles at the center and
(motivate) its converse.
2. (Motivate) The perpendicular from the center of a circle to a chord bisects
the chord and conversely, the line drawn through the center of a circle to
bisect a chord is perpendicular to the chord.
3. (Motivate) There is one and only one circle passing through three given
4. (Motivate) Equal chords of a circle (or of congruent circles) are equidistant
from the center(s) and conversely.
5. (Prove) The angle subtended by an arc at the center is double the angle
subtended by it at any point on the remaining part of the circle.
6. (Motivate) Angles in the same segment of a circle are equal.
7. (Motivate) If a line segment joining two points subtendes equal angle at two
other points lying on the
same side of the line containing the segment, the four points lie on a circle.
8. (Motivate) The sum of the either pair of the opposite angles of a cyclic
quadrilateral is 180o and its converse
7. CONSTRUCTIONS (10)
1. Construction of bisectors of line segments & angles, 60o, 90o,
45o angles etc., equilateral triangles.
2. Construction of a triangle given its base, sum/difference of the other two
sides and one base angle.
3. Construction of a triangle of given perimeter and base angles.
UNIT V : MENSURATION
1. AREAS (4)
Area of a triangle using Hero's formula (without proof) and
its application in finding the area of a quadrilateral.
2. SURFACE AREAS AND VOLUMES (10)
Surface areas and volumes of cubes, cuboids, spheres (including hemispheres) and
right circular cylinders/cones.
UNIT VI : STATISTICS AND PROBABILITY
1. STATISTICS (13)
Introduction to Statistics : Collection of data, presentation of data --
tabular form, ungrouped / grouped, bar graphs, histograms (with varying base
lengths), frequency polygons, qualitative analysis of data to choose the correct
form of presentation for the collected data. Mean, median, mode of ungrouped
History, Repeated experiments and observed frequency approach to probability.
Focus is on empirical probability. (A large amount of time to be devoted to
group and to individual activities to motivate the concept; the experiments to
be drawn from real - life situations, and from examples used in the chapter on
Evaluation of activities
Courtesy : CBSE.NIC.IN