You will learn by doing

1. JSS MAHAVIDYAPEETHA Mysore-04
JSS INSTITUTE OF EDUCATION, Sakleshpura
Name: Devraj K N Class: -8th Duration: 15 minutes
Subject: Mathematics Unit: -Probability
Sub Unit: Probability Teaching mode: Offline
Teaching
points
Pupil teacher learning activities Online
resources
*
Introduction
about
probability
* Meaning
and
definition
of the
probability
T: Good morning, Students
P: Good morning sir
T : according to Pierre Simon Laplace It
is remarkable that a science, which began
with the consideration of games of
chance should be elevated to the rank of
the most important subject of Knowledge
[ Showing the video about probability
and explaining the topic]
In everyday life, we come across
statements such as
(1) It will probably rain today.
(2) I doubt that he will pass the test.
https://images
.app.goo.gl/3
AQ69QrFTV
9bvbeq8

2. (3) Most probably, Kavita will stand
first in the annual examination.
(4) Chances are high that the prices of
diesel will go up.
(5) There is a 50-50 chance of India
winning a toss in today's match.
P: sir actually what is the meaning of the
word probability ?
T: The words 'probably', 'doubt', 'most
probably', 'chances, etc., used in the
statements above involve an element of
uncertainty.
For example, in (1), 'probably rain' will
mean it may rain or may not rain today.
We are predicting rain today based on
our past experience when it rained under
similar conditions. Similar predictions
are also made in other cases listed in (2)
to (5).
The uncertainty of 'probably' etc. can be
measured numerically by means of
'probability' in many cases. Though
probability started with gambling, it has
been used extensively in the fields of
Video link of
the
Probability
https://youtu.
be/8cEB3dW
W7IM

3. Physical Sciences, Commerce, Biological
Sciences, Medical Sciences, Weather
Forecasting, etc.
T: ok students we will continue this topic
in the next class.
JSS MAHAVIDYAPEETHA Mysore-04
JSS INSTITUTE OF EDUCATION, Sakleshpura
Name: Devraj K N Class: -8th Duration: 15 min
Subject : Mathematics Unit: -Probability
Sub Unit: Probability Teaching mode: Offline
Teaching
points
Pupil teacher learning activity Online
resource’s
Solving
probability
Problems
with
example
T: Good afternoon, students.
P: Good Afternoon, Sir
T: in yesterday’s class we have studied
about what is probability
In this class we are going to do problems
based on probability
P: ok Sir.
T:
problem
example video
https://y
outu.be/
yUaI0Jr
iZty

4. Example 1-A coin is tossed 1000 times
with the following frequencies:
Head: 455. Tail: 545
Compute the probability for each event.
Solution: Since the coin is tossed 1000
times, the total number of trials is 1000.
Let us call the events of getting a head and
of getting a tail as E and F, respectively.
Then, the number of times E happens, ie,
the number of times a head come up, is
455,
So,
the probability of
E=
i.e., P(E)= =0.455
Similarly, the probability of the event of
getting a tail=

5. P(F)=
= 0.545
Note that in the example above, P(E) +
P(F)=0.455+0.545=1, and E and F are the
only two possible outcomes of each trial.
T: Are you all understand this problem.
P: Yes. Sir
T: let me take another example
Example 2: Two coins are tossed
simultaneously 500 times, and we get
Two heads: 105 times
One head: 275 times
No head: 120 times
Find the probability of occurrence of each
of these events.
Solution: Let us denote the events of
getting two heads, one head and no head

6. by E1 E2, and E3, respectively. So,
P(E1) = =0.21
P(E2)= = 0.55
P(E3)= =0.24
Observe that P(E1)+P(E2) + P(E3) = 1. Also
E1 E2 and E3 cover all the outcomes of a
trial.
Homework
1. In a cricket match, a batswoman hits a
boundary 6 times out of 30 balls she plays.
Find the probability that she did not hit a
boundary.
2. Refer to Example 5, Section 14.4,
Chapter 14. Find the probability that a

7. student of the class was born in August.
3)A die is thrown 1000 times with the
frequencies for the outcomes 1,2,3, 4, 5
and 6 as given in the following table:
Outcome 1 2 3 4 5 6
Frequency 179 150 157 149 175 190
T: let me continue this topic in the next
class

8. JSS MAHAVIDYAPEETHA Mysore-04
JSS INSTITUTE OF EDUCATION, Sakleshpura
Name: Devraj K N Class: -8th
Unit: -Area of parallelograms and triangles
Sub Unit: Area of parallelograms and triangles
Teaching mode: Offline Duration: 15 minutes
Teaching
points
Pupil Teacher learning
activity
Online Resource’s
Introduction
Of the topic
T: Good Morning students
P: Good morning, sir
T: Dear students
In Chapter 2, you have seen
that the study of Geometry,
originated with the
measurement of earth (lands)
in the process of recasting
boundaries of the fields and
dividing them into
appropriate parts. For
example, a farmer Budhia

9. had a triangular field and she
wanted to divide it equally
among her two daughters
and one son. Without
actually calculating the area
of the field, she just divided
one side of the triangular
field into three equal parts
and joined the two points of
division to the opposite
vertex. In this way, the field
was divided into three parts
and she gave one part to each
of her children. Do you think
that all the three parts so
obtained by her were
P: in fact, equal in area?
T: yes To get answers to this
type of questions and other
related problems, there is n
need to have a relook at
areas of plane figures, which
you have already studied in
earlier classes.
https://images.app.go
o.gl/s4bZckbXcFUQX1
RX6

10. You may recall that the part
of the plane enclosed by a
simple closed figure is called
a planar region
corresponding to that figure.
The magnitude or measure of
this planar region is called its
area. This magnitude or
measure is always expressed
with the help of a number (in
some unit) such as 5 cm, 8
m³. 3 hectares etc. So, we
can say that area of a figure
is a number (in some unit)
associated with the part of
the plane enclosed by the
figure.
We are also familiar with the
concept of congruent figures
from earlier classes and from
Chapter 5. Two figures are
called congruent, if they
have the same shape and the
same size. In other words, if
two figures A and B are
https://youtu.be/PKzE
3OWxDfq
From text book

11. congruent (see Fig. ), then
using a tracing paper,

12. JSS MAHAVIDYAPEETHA Mysore-04
JSS INSTITUTE OF EDUCATION, Sakleshpura
Name: Devraj K N Class: -8th
Unit: -Area of parallelograms and triangles
Sub Unit: Area of parallelograms
Teaching mode: Offline Duration: 15 minutes
Teaching
points
Pupil teacher learning activity Online
resource’s
Explaining
theorem
T: Good morning students
P: Good morning, Sir
T: dear students in yesterdays class we
have studied about introduction of area
of parallelograms
Today based on that we have to do some
theorems
P: ok sir
T: : Parallelograms on the same base and
between the same parallels are equal in

13. area.
Proof: Two parallelograms ABCD and
EFCD, on the same base DC and
between the same parallels AF and DC
are given (see Fig.11.12).
We need to prove that ar (ABCD)=ar
(EFCD).
In ∆ADE and ∆BCF
<DAE= <CBF (Corresponding angles
from AD || BC and transversal
AF) ...........(1)
<AED=<BFC (Corresponding angles
from ED || FC and transversal
AF) ..........(2)
Therefore, <ADE=<BCF (Angle sum
property of a triangle)
Also,
AD=BC (Opposite sides of the
parallelogram ABCD ).......(4)
So,
∆ADE =∆BCF [By ASA rule, using
https://images
.app.goo.gl/Rh
pzQbXavjZWT5
2A
https://youtu.b
e/MvfmQHxw8
A

14. (1), (3), and (4)]
Therefore, ar (ADE)= ar (BCF)
(Congruent figures have equal
areas).........(5)
Now,
ar (ABCD)=ar(ADE)+ar(EDCB)
=ar (BCF)+ar (EDCB)
=ar (EFCD)
So, parallelograms ABCD and EFCD are
equal in area.
T: OK students we will continue this
topic in the next class

15. JSS MAHAVIDYAPEETHA Mysore-04
JSS INSTITUTE OF EDUCATION, Sakleshpura
Name : Devraj K N Class: -8th
Unit: -Area of parallelograms and triangles
Sub Unit: Area of parallelograms and triangles
Teaching mode: Offline Duration: 15 minutes
Teaching
points
Teacher pupil learning activity Online resources
Explaining
the theorem
T: Good afternoon students
P: Good afternoon, Sir
T:In yesterdays class we have
studied about the parallelogram
theorem let me do another
theorem

16. Triangles on the same Base
and between the same
Parallels
Let us look at Figure In it, you
have two triangles ABC and
PBC on the same base BC and
between the same parallels BC
and AP.
P: What can you say about the
areas of such triangles?
T: To answer this question, you
may perform the activity of
drawing several pairs of
triangles on the same base and
between the same parallels on
the graph sheet and find their
areas by the method of counting
the squares: Each time, you will
find that the areas of the two
triangles are (approximately)
equal. This activity can be
performed using a geoboard
also. You will again find that the
two areas are (approximately)
equal.
https://images.app.go
o.gl/cP9BEuDhrHBzmu
ou9

17. Figure
To obtain a logical answer to the
above question, you may
proceed as follows:
In Fig. 1, draw CD ||BA and CR
|| BP such that D and R lie on
line AP(see the second figure).
From this, you obtain two
parallelograms PBCR
and ABCD on the same hase BC
and between the
same parallels BC and AR
Fig. 2
Therefore,
ar (ABCD) ar (PBCR)
P:Why?
https://images.a
pp.goo.gl/rub3F3
modrTTiHoe7
https://youtu.
be/yyP3IXw4g
ZQ

18. T: Now
∆ ABC= ∆CDA and ∆PBC=
∆CRP
P: Why?
So.
ar (ABC)=(1/2)ar (ABCD) and
ar (PBC)=(1/2ar) (PBCR)
P:Why?
T: Therefore,
ar (ABC)= ar (PBC)
In this way, you have arrived at
the following theorem:
T: dear students let me continue
this topic in the next class