Answer :
As given angle of one sector = 120°
So,angle of other sector = 360° - 120° = 240°
So,difference of areas of two sectors of angles 240° and 120° is :
[tex] \frac{240}{360} \times \frac{22}{7} \times 21 \times 21 - \frac{120}{360} \times \frac{22}{7} \times 21 \times 21[/tex]
[tex] = 924 - 462 = 462 \: m {}^{2} [/tex]
So,angle of other sector = 360° - 120° = 240°
So,difference of areas of two sectors of angles 240° and 120° is :
[tex] \frac{240}{360} \times \frac{22}{7} \times 21 \times 21 - \frac{120}{360} \times \frac{22}{7} \times 21 \times 21[/tex]
[tex] = 924 - 462 = 462 \: m {}^{2} [/tex]