LESSON PLAN EXPERIMENT CLASS
School : SMP Negeri 1 Ungaran
Subject : Mathematics
ClassSemester : VIII2
nd
Time Allocation : 2 x 40 minutes 2
nd
meeting
A. Standard competence
4. Determining the element of circle, its parts and its size.
B. Basic competence
4.3 Applying the relationship of central angle, the length of the arc and area of sector.
C. Indicators 4.3.2 Determining the length of arc, the area of sector and the area of segment.
D. Learning Objectives
1. Students are able to determine the length of arc. 2. Students are able to determine the area of sector.
3. Students are able to determine the area of segment.
E. Learning Materials
b. The relationship of central angle, inscribed angle, length of arc, and area of sector
Sector is a region bounded by a central angle and its intercepted arc Clemens, 1983: 421.
Picture 2.1 r
B A
O
In the picture 2.1, if then area of sector AOB:
In picture 2.1 curve AB is arc of circle. Then, length of arc AB:
In the picture 2.2, if then the ratio
of central angle = the ratio of arc’s length = the ratio of sector’s area. We can write:
F. Learning Method and Model
Method : Speech Discussion
Question answer Model
: Course Review Horay Picture 2.2
P
O B
A Q
G. Learning Activities
Activity Polya Steps
CRH Activity
Standard process
Opening Activity 5 ‟
a. Teacher starts the class by greeting. b. Teacher prepares physical and
psychological conditional
of students by checking the attendan-
ce list and asking the students to prepare all of the mathematics
books.
c. Teacher motivates students by saying that the material is quite
important and deserved to be learnt.
Core Activities 67‟
Phase 1. Present goals and set
2’
1.1 Teacher informs the learning objectives and the scope of the
material. Phase 2:
Present Information 25’
2.1. Teacher checks the prerequisite ability of students about the
perimeter and area of circle by question answer.
2.2. Teacher presents the material about how to determine the length
of arc and area of sector using mathematics models.
2.3. Teacher gives opportunity to students to ask if there is
material that are not understood yet.
2.4 Teacher asks students to write down the important materials in
their writing book. 2.5 Teacher gives problems that
related to the length of arc, and area of sector. zone of proximal
development
2.6 Teacher guides students to Understand
Inform the competence
Present the materials
Question and answer
Exploration
Exploration
Exploration
Elaboration
Elaboration
Elaboration
understand the
problems. scaffolding
2.7 Teacher guides students to see how the various items are
connected, and make a plan to solve the problems. scaffold-
ding
2.8 Teacher guides students to carry out the plan. scaffolding
2.9 Teacher guides students to look back at the completed solution.
scaffolding
Phase 3. Organize students into
learning teams 5’
3.1. Teacher organizes students into
