The document discusses formulas for calculating the area of a sector of a circle. It explains that the area of a sector is proportional to the central angle subtended, and provides the formula for calculating sector area given the radius and central angle. Examples are given for calculating sector area, radius given area and central angle, and central angle given radius and area. The document also provides the formula for calculating the area of a full circle.

1. Group 5

2. The Formula for the area of sector
 The Length of an arc is proportional to the angle
subtended at the centre of the circle
 Similarly, the area of a sector is also proportional to
the angle subtended at the centre of the circle
 The area of a sector of a circle can be calculate by
using this formulae

3. Find The Area Of a Sector given the
radius and angle at the centre
A
O B
7 cm
Formulae
Solution

4. Find The Angle Of The Centre.
Given the radius and area of sector

A
O
B

5. Find The Radius. Given The Area Of A
Sector And The Angle Of The Centre
A
O
B

6. Solve The Problem
Find The Area Of Sector
A
O
B
In the diagram, O is the centre
of the circle. Find the area
of Major Sector AOB.
Answer

7. Find The Area Of Circle
O 14cm
In the diagram, O is the centre
of the circle. Find the Area Of Circle.
With the radius 28cm
Answer

8. Circles Formula
Area Of Sector CircleArea Of Circle
Circumference of Circle Length Of Arc