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1. Lesson template
Name of the teacher: Sai Priya S
Subject : Mathematics
Unit : Similar Triangles
Topic : Concept of similarity
Focus
To make the students understand the concept of similarity and to teach
them how to cultivate the talent of solving similarity problems.
Social system
To teach the students about the concept of similarity, the teacher shows
the students some shapes as examples. Students observe the shapes and
group them. From that they come into the conclusion of the concept and
thereby solving the problems related to similarity.
Principles of reaction
With the help of observing the students and grouping them accordingly the
teacher makes the students understand the concept of similarity.
Support system
Shapes, coins, textbook etc.

2. Classroom Interaction Procedure
Phase I: Collection and observation
The teacher displays some shapes to the students and asks them
to observe. Later, asking them to group the shapes.
Responses

3. Classroom
Interaction
Procedure
Phase II:
Classification
The teacher
asks the
students to
group these
shapes.
Responses
Stage I
A B

4. Classroom
Interaction
Procedure
Again the
teacher asks
the students
to group the
shapes in
both A and B.
Responses
Stage II
A B C D E F

5. Classroom
Interaction
Procedure
Teacher asks
the students
to group the
shapes with
similar shape
but different
size.
Responses
Stage III
A B C D E F

6. Classroom Interaction Procedure
Phase III: Suggesting the basis of
classification
Teacher asks the students on what basis the
three stages are been grouped.
Phase IV: Developing facts
Teacher ask the students to identify the
speciality of A, B, C, D etc from stage III.
Phase V: Concept formation
Therefore, such shaped or 3-D figures which
have the same shape but different size is said
to be similar in nature.
Responses
Stage I
Grouped as shapes and 3-D
figures.
Stage II
Grouped as similar shapes
Stage III
Grouped as similar shapes but
different sizes.
1. Same shapes or 3-D figures
2. Similar shapes
3. Different sizes

7. Classroom Interaction Procedure
So how can we conclude the concept of
similarity?
Phase VI: Problem solving
The teacher asks the students the following
question.
Which of these are similar?
Responses
Two geometrical objects are said
to be similar if they both have the
same shape, or one has the same
shape as the mirror image of the
other.

8. Follow up activity
1. Find out 4 sets of similar shapes from the nature?
2. Using a scale, find out these two hexagons are similar?