1. EteMS
KHOO SIEW YUEN
SMK.HI-TECH
2005

2. Topic : Circuler Meassure
Area of Sector

3. Mathematic Skills
1. Determine
- area of sector radius
- the radius
- the angle subtended center of a circle
2. Find the area of segment of circle
Prior Knowledge
The students already learnt
how to convert measurement in radians to degrees and vice versa.
how to determine the length of arc, radius and angle subtended at the
centre of a circle.
- how to find the perimeter of the segment of circle.

4. Learning Outcomes:
At the end of this lesson, students will be able to:
find the area of sector radius, the radius and the angle subtended center of a
circle.
- answer the quiz 100% correctly.
- answer at least 3 out of 5 questions given in the worksheet correctly.
CONNECT TO LESSON PLAN

5. Area of Sector
Area
Quiz
Radius
Angle
Worksheets

6. What is Area Sector of circle???
Like that???

7. And this is a circle with sector AOB.
The area shaded blue color names as
Area AOB.
This is a circle with center O. O

8. A A
r cm O
A=Area Shaded
r = radius B

9. Diagram below shows a circle with 4cm radius and angle 270 o,
find the shaded area.
Given r=4cm, angle = 270 o
r=4 cm O
270o

10. 2. Find the angle of the sector AOB in radiant.
= 270o x

11. = 270o x
Given r = r cm
Perimeter = 90cm
Arc AB + OA + AB = 90cm
50 + r + r = 90cm
2r = 40
r = 40
3. Diagram above shows a sector AOB
with center O made from wire length
90cm, the length of arc OAB is 50cm,
find : -
the angle in radiant
The area of sector AOB

12. 4. A circle sector with area 25. 2cm2 and the angle at the centre is 1
4. A circle sector with area 25.2cm2 and the angle at the centre is 1.4rad.
Find the radius of the circle.

13. 5. Find the area of minor sector AOB.
= 270o x