Question

Radius of the sector of the circle is 7cm.if measures of arc of the sector is 1)30°
2)210°
3) three right angles

Answer 1

Area of sector when arc subtending 30

= pie r^2× 30/360 = pie r^2/12

= 22/7 × 7 × 7 /12

= 22× 7/12 = 154/12 = 12.8 cm^2

2) area when subtending 210

= pie r^2 × 210/360

= 22× 7 × 7/12

= 22× 49/12 = 1078/12 = 89.83

3)Three right means 270

Area of circle - Area of sector subtending 90

= pie r^2 - pie r^2 × 90/360

= pie r^2( 1 - 1/4)

= 3/4 × pie r^2

= 3× 22 × 7/4 = 462/4 = 115.5 cm^2