RS Aggarwal - Mathematics

Book: RS Aggarwal - Mathematics

Chapter: 18. Area of Circle, Sector and Segment

Subject: Maths - Class 10th

Q. No. 11 of Exercise 18B

Listen NCERT Audio Books to boost your productivity and retention power by 2X.

11

A sector is cut from a circle of radius 21 cm. The angle of the sector is 150°. Find the length of the arc and the area of the sector.


Consider the circle shown above,


Given radius of the circle = R = 21 cm eqn1


And angle of the sector = θ = 150o eqn2


Length of arc of a sector


Where ‘R’ = radius of sector (or circle)


θ = angle subtended by the arc on the centre of the circle


Put the values of R and θ from equation 1 and 2 in equation 3





= 138600/2520


= 55 cm


Area of a sector


Where ‘R’ = radius of sector (or circle)


θ = angle subtended by the arc on the centre of the circle


Put the values of R and θ from equation 1 and 2 in equation 3




= 1455300/2520


= 577.5 cm2


The length of arc is 55 cm and area of sector is 577.5 cm2.


Chapter Exercises

More Exercise Questions