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21yo)it1the given figure, two cun centric oneswith centre O have radia 23 cs and 42m黑田 |
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Answer» Radii of the concentric circles = 21 cm and 42 cmArea between the circles = π R^2- r^2= (22/7) (42^2- 21^2) = 4158 cm^2Angle subtended by the arc in the inner circle = 60°Area of the sector in the inner circle = (60° / 360°) x π r^2= (60° / 360°) x (22/7) x (21)^2= 231 cm^2Angle subtended by the arc in the outer circle = 60°Area of the sector in the inner circle = (60° / 360°) x π R^2= (60° / 360°) x (22/7) x (42)^2= 924 cm^2Area of the portion of the sector in between the circles = 924 - 231 = 693 cm^2Area of the shaded portion = (Area between the circles) - (Area of the portion of the sector in between the circles) = 4158 - 693 = 3465Therefore, the area of the shaded region is 3465 cm^2. succser of next digit 64799 |
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