Question

solve questions number 16 plz it's argent

Answer 1

area of large circle - area of small circle - area of minor sector of large circle.
then u can get right answer

Answer 2

Sol:Radii of the concentric circles = 21 cm and 42 cmArea between the circles = π R2 - r2 = (22/7) (422 - 212) = 4158 cm2Angle subtended by the arc in the inner circle = 60°Area of the sector in the inner circle = (60° / 360°) x π r2 = (60° / 360°) x (22/7) x (21)2 = 231 cm2 Angle subtended by the arc in the outer circle = 60°Area of the sector in the inner circle = (60° / 360°) x π R2 = (60° / 360°) x (22/7) x (42)2 = 924 cm2Area of the portion of the sector in between the circles = 924 - 231 = 693 cm2Area of the shaded portion = (Area between the circles) - (Area of the portion of the sector in between the circles) = 4158 - 693 = 3465
Hence the area of shaded region is 3465cm^2