Question

The radius of a sector is 21 cm with an included angle of 120 degrees. What is the area of the sector, in square centimetres?
A) 462
(B) 698
(C) 924
(D) 1386

Answer 1

Answer:

Here,r=21cm, angle of sector is(¶) 120°

area of sector = πr²¶/360°

=22/7×21×21×120°/360°

=22×3×21/3

=22×21

=462cm²

Answer 2

Answer:

A) 462

Step-by-step explanation:

angle=120°

Radius,R=21 cm

Circumference of the base = Length of an arc

2*pi*r=(theta/360°)* 2* pi* R

r= ( 120/360°) * 21

=7 cm

Slant height= radius of the sector

l= 21 cm

CSA =pi*r* l

=(22/7)*21

=462 Sq.cm

Thus, CSA of cone =462 sq.cm