1) The document outlines a lesson plan for teaching students about circles and solving problems related to circles. It includes learning outcomes, pre-requisites, teaching-learning activities, and a step-by-step description of how the teacher will present the problem and guide students to prove that if the bisector of an angle formed by two chords is a diameter, then the chords are equal in length. 2) The teacher will begin by reviewing concepts like congruent triangles and presenting the problem. Through a series of activities, the teacher will have students recognize that two triangles formed are congruent, which allows them to prove the chords are equal in length. 3) The lesson concludes with the teacher summar

1. CURRICULAR STATEMENT: To understand about the problem of circle
and its importance in mathematics through
observation, organization of charts and by
analysing prepared notes of the pupil
CONTENT ANALYSIS
New term: Bisector
Fact : If two angles of two triangles are equal then the third angle
also will be equal
Concept : Concept of problem on circle
Process : Process of understanding the problem of circle
LEARNING OUTCOMES
The pupils will be able to:
1) Recall the term chord
2) Recognize perpendicular bisector of chord
3) Identify the condition for two triangles to be congruent
4) Give illustration for congruent triangle
5) Detect errors while solving the problem
Name of the teacher: Saranya U N
Subject : Mathematics
Unit : Circles
Subunit :Circle-
problem
Name of the school: MTGHSS
Pathanapuram
Standard :1X A
Strength :40/44
Date :4/08/2015
Time :35 minutes

2. 6) Suggest a different method to solve the problem
7) Discuss the problem of circle with other students
8) Try to find some fresh clues to solve the problem
9) Read charts quickly and accurately on the problem of circle
10)Plan to do problem on circle
PRE-REQUISITES : The students have knowledge on congruent
triangle, chord of circle, etc
TEACHING-LEARNING: Usual classroom aids, charts
RESOURCES
LEARNING STRATEGIES: Observation, activity, observing charts and
explanation by the teacher

3. Classroom interaction procedure Expected pupil responses
INTRODUCTION
ACTIVITY 1
1) What is a congruent triangle?
2) What are the conditions for
two triangles to be
congruent?
Through these questions,
teacher leads students to the
topic
PRESENTATION
ACTIVITY 2
Teacher presenting the problem
and ask students to write the
problem in notebook.
“AB and AC are two chords of a
circle and the bisector of <BAC is a
diameter of the circle. Prove that
AB=AC”
A
B
C [BB]
All students respond
Some students not respond
All students write the problem on
notebook

4. ACTIVITY 3
[BB]
Teacher says that, here AD is the
diameter; O is the centre and OM,
ON are perpendicular drawn from
O to AB and AC respectively.
Consider ∆AMO and ∆ANO,
˂MAO=˂NAO, What will be the
reason?
AO is the common side fo4r both
the triangles.
<AMO=<ANO=90°
Can we say <AMO=<ANO?
What will be the reason?
ACTIVITY 4
Teacher says that if one side and
two angles on that side of a
triangle are equal to one side and
two angles on that side of the
other triangle, then two triangles
Students respond that since AD is
the bisector of <BAC
Yes
Because if two angles of two
triangles are equal then the thirds
angle also will be equal.

5. are congruent.
So what can we say?
Here AM=AN, why?
We know that OM and ON are
perpendicular from centre to the
chords AB and AC. So what can we
say?
ACTIVITY 5
Teacher presenting chart in
classroom. That contain,
The method of proving the
theorem.
Teacher asks students to loudly
read the chart in the order of one
student from one bunch.
ACTIVITY 6
From the theorem what can we
say about AM and AN?
AM=AN
Also,
AM=
1
2
𝐴𝐵
AN=
1
2
AC
therefore
1
2
𝐴𝐵=
1
2
AC
Students respond that we can say
∆AMO and ∆ANO are congruent.
Since AM and AN are
corresponding sides of congruent
triangles
Students not respond
Students read the chart and write
the steps on notebook
Students respond that,
AM=
1
2
AB
AN=
1
2
AC

6. AB=AC
[BB]
CLOSURE
ACTIVTY 6
Teacher summarizes the method
of solving the problem by
repeating main points in the
problem
REVIEW
ACTIVITY 7
Teacher review the lesson by
giving questions related to the
topic.
FOLLW UP ACTIVITY
If PQ and PR are two chords of a
circle and the bisector of <QPR is a
diameter of the circle. Prove that
PQ=PR
All students carefully listen