THE CIRCLE AREA

The Draft of task lecture Media Pembelajaran Berbasis ICT
Lecturers : Budi Mulyono, Dr.Somakim, Jaidan Jauhari
By : Circle Area Group
1. Dinal ‘Ulya
2. Rahma Siska Utari
3. Asia Kurniasari
4. Septi Maulina Sari
5. Okwan Wamancha
6. Desi Arisandi

A.Teacher Manual
Circle is the set of all points on the field within a certain distance, called the radius (r), from a certain point, called the center. The circle is an example of simple closed curves, dividing the field into the inside and outside.


Radius (r) is a straight line that connects the centre with a circle
Diameter (d) is the largest bow string whose length is twice the radius. It shares the same area of a circle diameter
d=2r
Circumference (C) circumference of a circle is the longest arc on the circle
C=2πr


Area of circle can be calculated with the cut it up as an element of the cake and then reassembled into a rectangle whose width can be easily calculated.

If a rectangle has length (l ) and width (w) it has area A = lw
Supposing between circle area and rectangle area, leght is a half of circle circumference and width is a radius in circle.
Therefore, A = lw
A= 1/2(2πr)r
A=πr^2
1. Teacher divides students into small groups, where one group consists of 3 people. This is so that students more easily understand and discuss in groups if there are explanations that are not understood. This also avoids a large group discussion for all students to be active in groups
2. In one group there is at least (minimum) 1 PC to facilitate part of the learning process.
3. Students are required to understand and to master and apply what they have learned.

B.Students Activity
1. Students make a circle with center O and radius r
2. Students can divide the circle into several equal parts (divided in 18 equal pie)
* Students know the corner of a large circle round (3600)
*Students can divide the angle into 18 sections and determine the amount of angle is obtained from the results for (3600 : 18= 200)
3. Students set the pie - pie circle into a rectangular shape
4. Students know the circumference of a circle formula
5.Students know the area of rectangle
6.Students can find area of circle with connect the circumference circle formula and the area of rectangle
7.Student find the area of circle.