Question

A sector is cut-off from a circle of radius 21cm. The angle of the sector is 120°. Find the length of its arc and the area.

Answer 1

Refer the Image

1. Length of the arc = 66 cm

2. Area of sector = 464 cm^2

Answer 2

Length of arc = 44 cm

Area of the sector = 462 cm²

Step-by-step explanation:

Given  radius 21 cm and angle of the sector = 120 degrees

 So length of arc = (θ/360)(2πr)  

  = 120/360 * 2 * 22/7 * 21

  = 44 cm

Area of the sector =  (θ/360)(πr²)  

  = 120/360 * 22/7 * 21 * 21

  = 22 * 21

  = 462 cm²