1. The document is a lesson plan for teaching 8th standard students about isosceles triangles in mathematics. 2. It outlines the objectives, concepts, principles and process that will be used to help students understand the characteristics of isosceles triangles. 3. The lesson plan involves showing students examples of different types of triangles, demonstrating how to identify an isosceles triangle, and having students work in groups on activities to recognize and draw isosceles triangles.

1. NEW B.Ed COLLEGE
NELLIMOODU
THIRUVANANTHAPURAM – 695524
INNOVATIVE LESSON PLAN
(SEMESTER-II)
B.Ed. COURSE 2013 – 2014
SUMI S. V.
MATHEMATICS
180/13376012

2. Name of the teacher : SUMI S. V. Standard : VIII
Name of the School : Division :
Name of the Subject : Mathematics Streenght :
Name of the Unit : Congruent triangles Duration : 45 mts
Name of the sub unit : Isosceles Triangles Date :
Curricular Statement : Understanding the issoscles Traingles
Terms : Isosceles Traingle
Facts : A Trinagle in which two sides are equal is called isosceles triangle.
Concept : The concept of isosceles traingle
Principle : 1. If two sides of a triangle are equal, then the angles oppsoite to these sides are also equal.
2. If two angles of a traingles are equal, then the sides opposite these angles are also equal.
Process : The process of finding the isoscles triangle
Learning outcomes
Pupil : 1. Remembering the information about the characteristics of isosceles triangle.
2. Develops understanding infinding the isosceles traingle
3. Applying the above information infamiliar situations.
4. Analysing the information to explore understanding and relation.
5. Justify the above concepts and formulas.
6. Creating new ideas related to the above facts and concepts.
7. Develops skills infinding the isosceles trianagle.
8. Develops interests infinding the characteristics of isosceles triamgle.
Pre Requisites : Isosceles triangle, Congruency
Teaching Learning Resources : Activity card, Chart

3. Classroom Interaction Procedure Pupil Response
Preparation :
The teacher asks the student to different types of triangles
The teacher asks the student to the isosceles traingles.
The teacher shows the models of traiangles with the help of slides.
Triangles
The different types of traingles Are
Then the teacher shows the slide of any triangle
A
B P C
Any triangle can be split into two right angled triangles, by drawing
a perpendicular from one vertex to opposite side.

4. Then show the another slide
A triangle with two of its sides equal can be split into two
congruent right angled triangles. We need only draw the
perpendicular from the vertex where the equal sides meet,
to the opposite side.
Development
The teacher divide the students into four groups and for each group the activity.
To draw the triangle in which two sides are equal and then draw perpendicular from the vertex
where the equal sides meet, to the opposite side.
Then the students draw a triangle.
The teacher shows the another slide
P
In this figure AB = AC in ABC. The line AP is drawn perpendicualr to the side BS. The ABC
is divided into two right angled triangles ABP and ACP. They are congruent. So their sides must
be equal.

5. Then the teacher shows the clear definition of isosceles triangle
Isosceles Traingle
If two sides of a triangle are equal, then the angles opposite to there sides are also equal.
P
Is the resverse true?
That is, if two angles of the triangle are equal, are the sides opposite them also equal?
The teacher shows the another slide.

6. P
In this triangle AP is a common side. And one angle on this side is 900 in both triangles
Since the sum of the angles of any triangles is 1800.
We have in ABP
<ABP + <BAP +900 = 1800
from which we get
<ABP + <BAP = 900 and hence
<BAP = 900 - <ABP
Similarly, from ACP, we get
<CAP = 900 - <ACP
If we use the fact that
<ABP = <ACP also we get
<BAP = <CAP
Thus the side AP of ABP and the angles APB and BAP on it are equal to the side AP of
ACP and the angles APC and CAP on it. So the triangles are congruent.

7. Then the teacher shows the another slide.
If two angles of a traingle are equal, then the sides opposite these angles are also equal
P
From the slide they reach the concept of a triangle in which two sides are equal. This triangle is called
isosceles triangle
To check whether the students understand the concept the teacher given a problem.

8. Application
1. Find the other two angles of the isoceles triangle
From the isosceles triangle
Two sides are equal so the sides opposite angles are equal
180 - (33+33) = 180 - 660 = 1140
Review
1. What are the properties of isoscles triangle?
Follow up Activity :
1. Find the other two angles?
What are the angles of an isosceles right angled triangle.
330
500