LESSON PLAN

Level : Junior High School

Subject : Mathematics

Class : IX

Semester : I

Topic : Geometry and Measurement

Standard Competence : 1. Understanding the similarity

of figures and the use in problem

solving

Time Allocation : 2 x 40 minutes

Standard Competence

1. Understanding the similarity of figures and the use in problem solving

Basic Competence

1.2 Identifying the properties of two similar and congruent triangles

Indicators

1. Identifying two congruent or incongruent figures by showing the

requirements.

2. Determining two congruent triangles.

3. Determining the proportions of the sides of two congruent triangles.

4. Mentioning the properties of two congruent triangles.

5. Mentioning the requirements of two triangles to be congruent.

6. Proving two congruent triangles.

7. Distinguishing the concept of similarity from congruency.

Learning Objectives

1. Given the general definition of congruency, students can identify two

congruent or incongruent figures from the models provided by teacher

by showing the requirements.

2. Given several pair of triangles, students are able to determine whether

they are congruent or not.

3. Given two congruent triangles, students can determine the proportions

of the sides of the two triangle.

4. Students are able to mention the properties of two congruent triangles.

5. Students are able to mention the requirements of two triangles to be

congruent.

6. Given two triangles, students can prove that they are congruent.

7. After learning about similarity and congruency, students are supposed

to be able to distinguish the concept of similarity from congruency.

Learning Model

Learning Model : Conceptual Teaching

Learning Approach : Direct Presentation

Learning Method : Lecture Method, Question-Answer Method

Learning Sources

Handbook

Learning Materials

White board and board markers

PowerPoint Presentation

Learning Activities

Apperception (± 10 minutes)

1. Phase 1. Clarify aims and establish set

o Teacher communicates the outlines of basic competence and

indicators that will be learnt.

o Teacher leads students to recall the lesson that had been learnt in

the previous meeting.

o Teacher prepares the material and sets students ready to learn.

Main Activities (± 60 minutes)

2. Phase 2. Input examples and nonexamples

o Teacher names the concept being learnt and informs it to the

students. In this case, the concept is congruency.

o Teacher explains the general definition of congruency.

o Teacher provides students several figures and asks students

whether the figures are congruent or not.

o Further, teacher provides students several pairs of congruent

triangles and asks students to determine the proportions of the sides

of the triangles.

o Teacher leads students to mention the properties of two congruent

triangles.

o Teacher then poses the conditions in which two triangles are said to

be congruent.

o Students, by the guidance of the teacher, try to conclude and

mention the requirements in which two triangles are said to be

congruent.

o If it is possible, teacher can provide more examples and

noexamples of congruent triangles by leading the students to give

reason why the triangles are said to be congruent.

3. Phase 3. Test for attainment

o To check whether students have mastered the concept of

congruency or have not, teacher can ask several students randomly.

The questions can vary from determining whether two triangles are

congruent or not to rementioning the properties of two congruent

triangles and the requirements in which two triangles are said to be

congruent.

o Teacher then can give small quiz to the students to check their

understanding entirely. The questions in the quiz may vary from

proving that two triangles are congruent to providing their own

examples and nonexamples of two congruent triangles with the

reason/s.

4. Phase 4. Analyze student thinking processes and integration of

learning

o Teacher gets students to think about their own thinking processes,

about what they have learnt from that meeting. Teacher can modify

this activity by asking students to summarize what they have learnt

that day in a piece of paper without taking a look at the book or any

other sources. The only source of the summarization is student

understanding.

o Teacher then collects student summarizations and informs the

students that the score they get from the summarization will

contribute to their score of the quiz.

o Teacher then leads the students to integrate this new concept (about

congruency) by relating this concept to the previous concept which

is similarity.

o Teacher leads the students to again recall the concept of similarity

and then to compare the concept of similarity with the concept of

frequency.

o Teacher helps students to distinguish the concept of similarity from

the concept of congruency.

Closure (± 10 minutes)

o Teacher leads students to conclude what they have learnt that day,

this can be modified by opening ‘question’ session.

o Teacher can also give homework to the students before closing the

lesson. The homework can be provided by the teacher or by the

book students have.

Assessment

The assessment can be done by assessing the quiz given. In assessing the

quiz, teacher should give feedback for each student.