Page 4 - Lesson note-Area of sector,length of Arc

P = 24 + 2 π

P = 24 + 6.28 = 30.28

Hence, Perimeter of sector is 30.28 cm

Example 3- A sector is cut from a circle of radius 21 cm. The angle of the sector
is 150 . Find the length of its arc and area.
o
Solution- The length of arc l and area A of a sector of angle θ in a circle of radius r are
given by,

t
360
and

t
360
respectively.

Here, r = 21 cm and θ = 150
t0
∴ t tt
360

t0 tt 2
t ​ = = 577.5 cm
360

4