LESSON PLAN Educational Unit

: Junior High School

Grade/Semester

: VII/II

Subject

: Mathematics

Allocation of Time

: 2 x 40 minutes

A. Standard Competence GEOMETRY 6. Understanding the concept of quadrilateral and triangle and determining the measure. B. Basic Competence 6.1 Identifying the properties triangle by the sides and angles. C. Indicators 1.

Explain the types of triangle by the sides. a) Identifying types of triangle based on the length of the side are that equilateral triangle, isosceles triangle, and scalene triangle. b) Classifying types of triangle based on the length of the side are that equilateral triangle, isosceles triangle, and scalene triangle.

2.

Explain the types of triangle by the angles. a) Identifying types of triangle based on the size of the angle are that acute triangle, right triangle, and obtuse triangle. b) Classifying types of triangle based on the size of the angle are that acute triangle, right triangle, and obtuse triangle

D. Learning Objectives 1. Students are able to identify and classify the types of triangle by length of the sides. 2. Students are able to identify and classify the types of triangle by the size of the angle. 3. Students can apply their knowledge about triangle in solving problem related to characteristics of triangle. E. Learning Activities : Learning Approach

: Indonesian Realistic Mathematics Education (IRME)

Learning Method

: Lectures, discussion, and assignment

Learning Media

: Computer based, LCD, and wireless based.

Created by. Dewi Hamidah | [email protected]

1

F. Learning Teaching Activity Teacher

Students

Introduction 1. Apperception: remind the student about

Time 10 minutes

 Students give respond and a

the lesson in the last meeting

bit explanation about the properties of rectangular

2. Goal : Teacher informs the students that

 Students give attention for the

they are going to learn about understanding the types of triangle

teacher explanation  Students listen the explanation

3. Teacher gives motivation to the students

the teacher

with explanation how important to study it Main Activity

60 minutes

Exploration 1. Students are divided into small group

 Students sit in their own group

2. Teacher gives the worksheet and the triangle cards. 3. Teacher asks students to work Activity 1 in  Students work their worksheet group just for the first number.

in each group

4. Teacher guides the students while they are working in group. 5. Teacher asks every group to explain and

 Students give explanation of their work

give the reason of their work in front of the class what based they classify it on. 6. Teacher guides students to identify and classify the types of triangles. 7. Teacher introduces the name of triangle by

 Students pay attention of teacher explanation

its properties. Elaboration 8. Teacher asks students to work Activity 1

 Students work in their each group

in group just for the second number. 9. Teacher asks every group to explain the definition each type of triangles.

 Students present and give explanation of their work

10. Teacher shows and explains the various of triangle by showing the pictures and definition that are taken from a website http://mathsisfun.com/triangle.html

 Students pay attention of

11. Teacher introduces the combining names

teacher explanation

of triangle. Created by. Dewi Hamidah | [email protected]

2

12. Teacher asks students to work Activity 1  Students work in their each in group just for the third number and

group

present their work. Confirmation 13. Students are asked to work Activity 2 in  Students present and answer

group. 14. Teacher guide the students answering the

the worksheet in Activity 2

question. 15. Each group presents their work. Closing

10 minutes

1. The teacher guides the students to make a  Students make a conclusion summary of the learning material they have learned. 2. Teacher gives the individual test to know  Students work the individual about students’ understanding the material.

test

3. Teacher gives homework and remedial (if needed). G. Lesson Instrument and Source 1. Instrument : Triangle Card, and Worksheet 2. Source : Textbooks H. Assessment the Result of Learning Indicators Achievement of Competence Explain the types of triangle by the length of the sides Explain the types of triangle by the size of the angle

Technique Discussion

Assessment Instrument Instrument/Worksheet Form Explanation

Verbal and Non Verbal Test

Explain the types of triangle by the sides and give the example with picture Explain the types of triangle by the size of angle and give the example with picture

Palembang, ……………………. 2012 Principal,

(……………................................) NIP.

Created by. Dewi Hamidah | [email protected]

Mathematics Teacher,

(…………………………………..) NIP.

3

Additional Material Teacher shows the various types of triangle on a website as a media.

Created by. Dewi Hamidah | [email protected]

4

Teacher shows the proof of the sum of angle is 180-degree.

Created by. Dewi Hamidah | [email protected]

5