Example 2 (Method 1)
Find the area of the sector of a circle with radius 4 cm and of angle 30°. Also, find the area of the corresponding major sector (Use π = 3.14).
Here,
radius = r = 4 cm, θ=30°
Now,
Area of sector = 𝜃/360×𝜋𝑟2
= 30/360×3.14×(4)2
= 1/12×3.14×4×4
= 1/3×3.14×4
= 12.56/3 cm2
= 4.19 cm2
Area of major sector = ((360 − θ))/360×𝜋𝑟2
= ((360 − 30))/360×3.14×(4)2
= 330/360×3.14×4×4
= 11/12×3.14×4×4
= 46.05 cm2
Example 2 (Method 2)
Find the area of the sector of a circle with radius 4 cm and of angle 30°. Also, find the area of the corresponding major sector (Use π= 3.14).
Here,
radius = r = 4 cm, θ=30°
Now,
Area of sector = 𝜃/360×𝜋𝑟2
= 30/360×3.14×(4)2
= 1/12×3.14×4×4
= 1/3×3.14×4
= 12.56/3 cm2
= 4.19 cm2
Area of major sector
= Area of circle – Area of minor sector
Here, radius = r = 4 cm
Area of circle = 𝜋𝑟2
= 3.14 × 42
= 3.14 × 16
= 50.24 cm2
Area of major sector
= Area of circle – Area of minor sector
= 50.24 – 4.19
= 46.05

Made by

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths and Science at Teachoo.